draft-ietf-nsis-req-02.txt   draft-ietf-nsis-req-03.txt 
NSIS Working Group NSIS Working Group
Internet Draft M. Brunner (Editor) Internet Draft M. Brunner (Editor)
Document: draft-ietf-nsis-req-02.txt NEC Document: draft-ietf-nsis-req-03.txt NEC
Expires: November 2002 May 2002 Expires: November 2002 May 2002
Requirements for QoS Signaling Protocols Requirements for QoS Signaling Protocols
<draft-ietf-nsis-req-02.txt> <draft-ietf-nsis-req-03.txt>
Status of this Memo Status of this Memo
This document is an Internet-Draft and is in full conformance This document is an Internet-Draft and is in full conformance with
with all provisions of Section 10 of RFC2026. all provisions of Section 10 of RFC2026.
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF), its areas, and its working groups. Note that Task Force (IETF), its areas, and its working groups. Note that
other groups may also distribute working documents as Internet- other groups may also distribute working documents as Internet-
Drafts. Drafts.
Internet-Drafts are draft documents valid for a maximum of six Internet-Drafts are draft documents valid for a maximum of six
months and may be updated, replaced, or obsoleted by other documents months and may be updated, replaced, or obsoleted by other documents
at any time. It is inappropriate to use Internet-Drafts as at any time. It is inappropriate to use Internet-Drafts as
reference material or to cite them other than as "work in progress." reference material or to cite them other than as "work in progress."
The list of current Internet-Drafts can be accessed at The list of current Internet-Drafts can be accessed at
http://www.ietf.org/ietf/1id-abstracts.txt http://www.ietf.org/ietf/1id-abstracts.txt
The list of Internet-Draft Shadow Directories can be accessed at The list of Internet-Draft Shadow Directories can be accessed at
http://www.ietf.org/shadow.html. http://www.ietf.org/shadow.html.
Informational [Page 1] Requirements for QoS Signaling Protocols July 2002
Requirements for QoS Signaling Protocols May 2002
Abstract Abstract
This document defines requirements for signaling QoS across This document defines requirements for signaling QoS across
different network environments. To achieve wide applicability of the different network environments, where different network environments
requirements, the starting point is a diverse set of scenarios/use across administrative and technology domains. To achieve wide
cases concerning various types of networks and application applicability of the requirements, the starting point is a diverse
interactions. We also provide an outline structure for the problem, set of scenarios/use cases concerning various types of networks and
including QoS related terminology. Taken with the scenarios, this application interactions. We also provide an outline structure for
allows us to focus more precisely on which parts of the overall QoS the problem, including QoS related terminology. Taken with the
problem needs to be solved. We present the assumptions and the scenarios, this allows us to focus more precisely on which parts of
aspects not considered within scope before listing the requirements the overall QoS problem needs to be solved. We present the
grouped according to areas such as architecture and design goals, assumptions and the aspects not considered within scope before
signaling flows, layering, performance, flexibility, security, and listing the requirements grouped according to areas such as
mobility. architecture and design goals, signaling flows, layering,
performance, flexibility, security, and mobility.
Table of Contents
Status of this Memo...................................................1
Abstract..............................................................2
Table of Contents.....................................................2
1 Introduction.......................................................4
2 Terminology........................................................5
3 Problem Statement and Scope........................................8
4 Assumptions and Exclusions........................................10
4.1 Assumptions and Non-Assumptions...............................10
4.2 Exclusions....................................................11
5 Requirements......................................................12
5.1 Architecture and Design Goals.................................13
5.1.1 Applicability for different QoS technologies................13
5.1.2 Resource availability information on request................13
5.1.3 Modularity..................................................13
5.1.4 Decoupling of protocol and information it is carrying.......14
5.1.5 Reuse of existing QoS provisioning..........................14
5.1.6 Independence of signaling and provisioning paradigm.........14
5.2 Signaling Flows...............................................14
5.2.1 Free placement of QoS Initiator and QoS Controllers functions14
5.2.2 No constraint of the QoS signaling and QoS Controllers to be in
the data path.....................................................14
5.2.3 Concealment of topology and technology information..........15
5.2.4 Optional transparency of QoS signaling to network...........15
5.3 Additional information beyond signaling of QoS information....16
5.3.1 Explicit release of resources...............................16
5.3.2 Possibility for automatic release of resources after failure 16
5.3.3 Prompt notification of QoS violation in case of error/failure
to QoS Initiator and QoS Controllers..............................16
5.3.4 Feedback about success of request for QoS guarantees........16
5.3.5 Allow local QoS information exchange between nodes of the same
administrative domain.............................................17
5.4 Layering......................................................17
5.4.1 The signaling protocol and QoS control information should be
application independent...........................................17
Requirements for QoS Signaling Protocols July 2002
5.5 QoS Control Information.......................................17
5.5.1 Mutability information on parameters........................17
5.5.2 Possibility to add and remove local domain information......18
5.5.3 Independence of reservation identifier......................18
5.5.4 Seamless modification of already reserved QoS...............18
5.5.5 Grouping of signaling for several microflows................18
5.6 Performance...................................................18
5.6.1 Scalability in the number of messages received by a signaling
communication partner (QoS initiator and controller)..............19
5.6.2 Scalability in number of hand-offs..........................19
5.6.3 Scalability in the number of interactions for setting up a
reservation.......................................................19
5.6.4 Scalability in the number of state per entity (QoS initiators
and QoS controllers)..............................................19
5.6.5 Scalability in CPU use (end terminal and intermediate nodes) 19
5.6.6 Low latency in setup........................................19
5.6.7 Allow for low bandwidth consumption for signaling protocol..19
5.6.8 Ability to constrain load on devices........................19
5.6.9 Highest possible network utilization........................19
5.7 Flexibility...................................................20
5.7.1 Aggregation capability, including the capability to select and
change the level of aggregation...................................20
5.7.2 Flexibility in the placement of the QoS initiator...........20
5.7.3 Flexibility in the initiation of re-negotiation (QoS change
requests).........................................................20
5.7.4 Uni / bi-directional reservation............................20
5.8 Security......................................................20
5.8.1 Authentication of signaling requests........................20
5.8.2 Resource Authorization......................................21
5.8.3 Integrity protection........................................21
5.8.4 Replay protection...........................................21
5.8.5 Hop-by-hop security.........................................21
5.8.6 Identity confidentiality and location privacy...............21
5.8.7 Denial-of-service attacks...................................22
5.8.8 Confidentiality of signaling messages.......................22
5.8.9 Ownership of a reservation..................................22
5.8.10 Hooks with Authentication and Key Agreement protocols......22
5.9 Mobility......................................................23
5.9.1 Allow efficient QoS re-establishment after handover.........23
5.10 Interworking with other protocols and techniques............23
5.10.1 Interworking with IP tunneling.............................23
5.10.2 The solution should not constrain either to IPv4 or IPv6...23
5.10.3 Independence from charging model...........................24
5.10.4 Hooks for AAA protocols....................................24
5.10.5 Interworking with seamless handoff protocols...............24
5.10.6 Interworking with non-traditional routing..................24
5.11 Operational.................................................24
5.11.1 Ability to assign transport quality to signaling messages..24
5.11.2 Graceful fail over.........................................24
6 The MUSTs, SHOULDs, and MAYs......................................24
7 References........................................................30
8 Acknowledgments...................................................30
Requirements for QoS Signaling Protocols July 2002
9 Author's Addresses................................................31
10 Appendix: Scenarios/Use cases...................................31
10.1 Scenario: Terminal Mobility.................................32
10.2 Scenario: Cellular Networks.................................34
10.3 Scenario: UMTS access.......................................34
10.4 Scenario: Wired part of wireless network....................36
10.5 Scenario: Session Mobility..................................38
10.6 Scenario: QoS reservations/negotiation from access to core
network............................................................38
10.7 Scenario: QoS reservation/negotiation over administrative
boundaries.........................................................39
10.8 Scenario: QoS signaling between PSTN gateways and backbone
routers............................................................39
10.9 Scenario: PSTN trunking gateway.............................41
10.10 Scenario: Application request end-to-end QoS path from the
network............................................................42
10.11 Scenario: QOS for Virtual Private Networks..................42
1 Introduction 1 Introduction
This document defines requirements for signaling QoS across This document defines requirements for signaling QoS across
different network environments. It does not list any problems of different network environments. It does not list any problems of
existing QoS signaling protocols such as RSVP. existing QoS signaling protocols such as RSVP.
In order to derive requirements for QoS signaling it is necessary to In order to derive requirements for QoS signaling it is necessary to
first have a clear idea of the scope within which they are first have a clear idea of the scope within which they are
applicable. applicable.
skipping to change at line 68 skipping to change at page 4, line 44
Appendix of that document. These scenarios derive from a variety of Appendix of that document. These scenarios derive from a variety of
backgrounds, and help obtain a clearer picture of what is in or out backgrounds, and help obtain a clearer picture of what is in or out
of scope of the NSIS work. They illustrate the problem of QoS of scope of the NSIS work. They illustrate the problem of QoS
signaling from various perspectives (end-system, access network, signaling from various perspectives (end-system, access network,
core network) and for various areas (fixed line, mobile, wireless core network) and for various areas (fixed line, mobile, wireless
environments). As the NSIS work becomes more clearly defined, environments). As the NSIS work becomes more clearly defined,
scenarios will be added or dropped, or defined in more detail. scenarios will be added or dropped, or defined in more detail.
Based on these scenarios, we are able to define the QoS signaling Based on these scenarios, we are able to define the QoS signaling
problem on a more abstract level. In Section 3, we thus present a problem on a more abstract level. In Section 3, we thus present a
simple conceptual model of the QoS signaling problem, describe the simple conceptual model of the QoS signaling problem. Additionally,
entities involved in QoS signaling, and typical signaling paths. In we describe the entities involved in QoS signaling and typical
Section 4 we list assumptions and exclusions. signaling paths. In Section 4 we list assumptions and exclusions.
The model of Section 3 allows deriving requirements from the The model of Section 3 allows deriving requirements from the
scenarios presented in the appendix in a coherent and consistent scenarios presented in the appendix in a coherent and consistent
manner. Requirements are grouped according to areas such as manner. Requirements are grouped according to areas such as
Architecture and design goals, Signaling Flows, Layering, Architecture and design goals, Signaling Flows, Layering,
Performance, Flexibility, Security and Mobility. Performance, Flexibility, Security and Mobility.
QoS is a pretty large field with a lot of interaction with other QoS is a pretty large field with a lot of interaction with other
protocols, mechanisms, applications etc. In the following, some protocols, mechanisms, applications etc. In the following, some
Requirements for QoS Signaling Protocols July 2002
thoughts from an end-system point of view and from a network point thoughts from an end-system point of view and from a network point
of view. of view.
End-system perspective: In future mobile terminals, the support of End-system perspective: In future mobile terminals, the support of
adaptive applications is more and more important. Adaptively can be adaptive applications is more and more important. Adaptively can be
seen as an important technique to react to QoS violations that may seen as an important technique to react to QoS violations that may
occur frequently, e.g., in wireless environments due to changed occur frequently, e.g., in wireless environments due to changed
Brunner, et al. Informational [Page 2]
Requirements for QoS Signaling Protocols May 2002
environmental and network conditions. This may result in degraded environmental and network conditions. This may result in degraded
end-to-end performance. It is then up to adaptive applications to end-to-end performance. It is then up to adaptive applications to
react to the new resource availability. Therefore, it is essential react to the new resource availability. Therefore, it is essential
to define interoperability between media-, mobility- and QoS to define interoperability between media-, mobility- and QoS
management. While most likely mobile terminals cannot assume, that management. While most likely mobile terminals cannot assume, that
explicit QoS reservation schemes are available, some access networks explicit QoS reservation schemes are available, some access networks
nevertheless may offer such capabilities. Applications subscribed to nevertheless may offer such capabilities. Applications subscribed to
an end-system QoS management system should be supported with a an end-system QoS management system should be supported with a
dedicated QoS API to set-up, control and adapt media sessions. dedicated QoS API to set-up, control and adapt media sessions.
skipping to change at line 119 skipping to change at page 5, line 41
and access routers or access network QoS managers (in the following and access routers or access network QoS managers (in the following
we call them QoS initiator and QoS controller). In the core network we call them QoS initiator and QoS controller). In the core network
QoS signaling refers to trunks or classes of traffic between core QoS signaling refers to trunks or classes of traffic between core
and edge systems or between peering core systems. Please note that and edge systems or between peering core systems. Please note that
this does not exclude the transport of per-flow signaling through this does not exclude the transport of per-flow signaling through
core networks. core networks.
It is clear from these descriptions that the subject of QoS is It is clear from these descriptions that the subject of QoS is
uniquely complex and any investigation could potentially have a very uniquely complex and any investigation could potentially have a very
broad scope - so broad that it is a challenge to focus work on an broad scope - so broad that it is a challenge to focus work on an
area which could lead to a concrete and useful result. This is our area, which could lead to a concrete and useful result. This is our
motivation for considering a set of use cases, which map out the motivation for considering a set of use cases, which map out the
domain of application that we want to address. It is also the domain of application that we want to address. It is also the
motivation for defining a problem structure, which allows us to motivation for defining a problem structure, which allows us to
state the boundaries of what types of functionality to consider, and state the boundaries of what types of functionality to consider, and
to list background assumptions. to list background assumptions.
There are several areas of the requirements related to networking There are several areas of the requirements related to networking
aspects which are incomplete, for example, interaction with host and aspects which are incomplete, for example, interaction with host and
site multi-homing, use of anycast services, and so on. These issues site multi-homing, use of anycast services, and so on. These issues
should be considered in any future requirement analysis work. should be considered in any future requirement analysis work.
2 Terminology 2 Terminology
In the area of Qualiaty of Service (QoS) it is quite difficult and In the area of Qualiaty of Service (QoS) it is quite difficult and
an exercise for its own to define terminology. Nevertheless, we an exercise for its own to define terminology. Nevertheless, we
tried to list the most often used terms in the draft and tried to tried to list the most often used terms in the draft and tried to
explain them. However, don't be to religious about it, they are not explain them. However, don't be to religious about it, they are not
meant to prescribe any thing in the draft. meant to prescribe any thing in the draft.
Requirements for QoS Signaling Protocols July 2002
Aggregate: a group of flows, usually with similar QoS requirements, Aggregate: a group of flows, usually with similar QoS requirements,
which can be treated together as a whole with a single overall QoS which can be treated together as a whole with a single overall QoS
requirement for signaling and provisioning. Aggregates and flows can requirement for signaling and provisioning. Aggregates and flows can
be further aggregated together. be further aggregated together.
Brunner, et al. Informational [Page 3]
Requirements for QoS Signaling Protocols May 2002
[QoS] Domain: a collection of networks under the same administrative [QoS] Domain: a collection of networks under the same administrative
control and grouped together for administrative purposes. control and grouped together for administrative purposes.
Egress point: the router via which a path exits a domain/subdomain. Egress point: the router via which a path exits a domain/subdomain.
End Host: the end system or host, for whose flows QoS is being End Host: the end system or host, for whose flows QoS is being
requested and provisioned. requested and provisioned.
End-to-End QoS: the QoS delivered by the network between two End-to-End QoS: the QoS delivered by the network between two
communicating end hosts. End-to-end QoS co-ordinates and enforces communicating end hosts. End-to-end QoS co-ordinates and enforces
skipping to change at line 194 skipping to change at page 7, line 5
domain/subdomain. domain/subdomain.
Mapping: the act of transforming parameters from QSCs to values that Mapping: the act of transforming parameters from QSCs to values that
are meaningful to the actual QoS technology in use in the are meaningful to the actual QoS technology in use in the
domain/subdomain. domain/subdomain.
Path: the route across the networks taken by a flow or aggregate, Path: the route across the networks taken by a flow or aggregate,
i.e. which domains/subdomains it passes through and the i.e. which domains/subdomains it passes through and the
egress/ingress points for each. egress/ingress points for each.
Requirements for QoS Signaling Protocols July 2002
Path segment: the segment of a path within a single Path segment: the segment of a path within a single
domain/subdomain. domain/subdomain.
QoS Administration Function: a generic term for all functions QoS Administration Function: a generic term for all functions
associated with admission control, policy control, traffic associated with admission control, policy control, traffic
engineering etc. engineering etc.
Brunner, et al. Informational [Page 4]
Requirements for QoS Signaling Protocols May 2002
QoS Control Information: the information the governs the QoS QoS Control Information: the information the governs the QoS
treatment to be applied to a flow or aggregate, including the QSC, treatment to be applied to a flow or aggregate, including the QSC,
flow administration, and any associated security or accounting flow administration, and any associated security or accounting
information. information.
QoS Controller: this is responsible for interpreting the signaling QoS Controller: this is responsible for interpreting the signaling
carrying the user QoS parameters, optionally inserting/modifying the carrying the user QoS parameters, optionally inserting/modifying the
parameters according to local network QoS management policy, and parameters according to local network QoS management policy, and
invoking local QoS provisioning mechanisms. Note that q QoS invoking local QoS provisioning mechanisms. Note that q QoS
controller might have very different functionality depending on controller might have very different functionality depending on
skipping to change at line 251 skipping to change at page 8, line 5
QoS Technology: a generic term for a set of protocols, standards and QoS Technology: a generic term for a set of protocols, standards and
mechanisms that can be used within a QoS domain/subdomain to manage mechanisms that can be used within a QoS domain/subdomain to manage
the QoS provided to flows or aggregates that traverse the domain. the QoS provided to flows or aggregates that traverse the domain.
Examples might include MPLS, DiffServ, and so on. A QoS technology Examples might include MPLS, DiffServ, and so on. A QoS technology
is associated with certain QoS provisioning techniques. is associated with certain QoS provisioning techniques.
QoS Violation: occurs when the QoS applied to a flow or aggregate QoS Violation: occurs when the QoS applied to a flow or aggregate
does not meet the requested and negotiated QoS agreed for it. does not meet the requested and negotiated QoS agreed for it.
Requirements for QoS Signaling Protocols July 2002
Resource: something of value in a network infrastructure to which Resource: something of value in a network infrastructure to which
rules or policy criteria are first applied before access is granted. rules or policy criteria are first applied before access is granted.
Examples of resources include the buffers in a router and bandwidth Examples of resources include the buffers in a router and bandwidth
on an interface. on an interface.
Brunner, et al. Informational [Page 5]
Requirements for QoS Signaling Protocols May 2002
Resource Allocation: part of a resource that has been dedicated for Resource Allocation: part of a resource that has been dedicated for
the use of a particular traffic type for a period of time through the use of a particular traffic type for a period of time through
the application of policies. the application of policies.
Sender-initiated QoS signaling protocol: A sender-initiated QoS Sender-initiated QoS signaling protocol: A sender-initiated QoS
signaling protocol is a protocol (see e.g., YESSIR [8], RMD [10]) signaling protocol is a protocol (see e.g., YESSIR [8], RMD [10])
where the QI initiates the signaling on behalf of the sender of the where the QI initiates the signaling on behalf of the sender of the
data. What this means is that admission control and resource data. What this means is that admission control and resource
allocation functions are processed from the data sender towards the allocation functions are processed from the data sender towards the
data receiver. However, the triggering instance is not specified. data receiver. However, the triggering instance is not specified.
Receiver-initiated QoS signalling protocol: A receiver-initiated Receiver-initiated QoS signaling protocol: A receiver-initiated
protocol, (see e.g., RSVP [9]) is a protocol where the QoS protocol, (see e.g., RSVP [9]) is a protocol where the QoS
reservations are initiated by the QoS Reiceiver on behalf of the reservations are initiated by the QoS Receiver on behalf of the
receiver of the user data. What this means is that admission control receiver of the user data. What this means is that admission control
and resource allocation functions are processed from the data and resource allocation functions are processed from the data
receiver back towards the data sender. However, the triggering receiver back towards the data sender. However, the triggering
instance is not specified. instance is not specified.
3 Problem Statement and Scope 3 Problem Statement and Scope
We provide in the following a preliminary architectural picture as a We provide in the following a preliminary architectural picture as a
basis for discussion. We will refer to it in the following basis for discussion. We will refer to it in the following
requirement section. requirement section.
skipping to change at line 307 skipping to change at page 9, line 4
the work, including any open issues. This model also identifies the work, including any open issues. This model also identifies
further sources of requirements from external interactions with further sources of requirements from external interactions with
other parts of an overall QoS solution, clarifies the terminology other parts of an overall QoS solution, clarifies the terminology
used, and allows the statement of design goals about the nature of used, and allows the statement of design goals about the nature of
the solution (see section 5). the solution (see section 5).
Note that this model is intended not to constrain the technical Note that this model is intended not to constrain the technical
approach taken subsequently, simply to allow concrete phrasing of approach taken subsequently, simply to allow concrete phrasing of
requirements (e.g. requirements about placement of the QoS requirements (e.g. requirements about placement of the QoS
initiator, or ability to 'drive' particular QoS technologies.) initiator, or ability to 'drive' particular QoS technologies.)
Requirements for QoS Signaling Protocols July 2002
Roughly, the scope of NSIS is assumed to be the interaction between Roughly, the scope of NSIS is assumed to be the interaction between
the QoS initiator and QoS controller(s), including selection of the QoS initiator and QoS controller(s), including selection of
signaling protocols to carry the QoS information, and the signaling protocols to carry the QoS information, and the
syntax/semantics of the information that is exchanged. Further syntax/semantics of the information that is exchanged. Further
Brunner, et al. Informational [Page 6]
Requirements for QoS Signaling Protocols May 2002
statements on assumptions/exclusions are given in the next Section. statements on assumptions/exclusions are given in the next Section.
The main elements are: The main elements are:
1. Something that starts the request for QoS, the QoS Initiator. 1. Something that starts the request for QoS, the QoS Initiator.
This might be in the end system or within some other part of the This might be in the end system or within some other part of the
network. The distinguishing feature of the QoS initiator is that it network. The distinguishing feature of the QoS initiator is that it
acts on triggers coming (directly or indirectly) from the higher acts on triggers coming (directly or indirectly) from the higher
layers in the end systems. It needs to map the QoS requested by layers in the end systems. It needs to map the QoS requested by
them, and also provides feedback information to the higher layers them, and also provides feedback information to the higher layers,
which might be used by transport layer rate management or adaptive which might be used by transport layer rate management or adaptive
applications. applications.
2. Something that assists in managing QoS further along the path, 2. Something that assists in managing QoS further along the path,
the QoS controller. the QoS controller.
The QoS controller does not interact with higher layers, but The QoS controller does not interact with higher layers, but
interacts with the QoS initiator and possibly more QoS controllers interacts with the QoS initiator and possibly more QoS controllers
on the path, edge to edge or possibly end to end. on the path, edge to edge or possibly end to end.
3. The QoS initiator and controller(s) interact with each other, 3. The QoS initiator and controller(s) interact with each other,
path segment by path segment. This interaction involves the exchange path segment by path segment. This interaction involves the exchange
of data (QoS control information) over some signaling protocol. of data (QoS control information) over some signaling protocol.
4. The path segment traverses an underlying network (QoS domain or 4. The path segment traverses an underlying network (QoS domain or
subdomain) covering one or more IP hops. The underlying network uses subdomain) covering one or more IP hops. The underlying network uses
some local QoS technology. This QoS technology has to be provisioned some local QoS technology. This QoS technology has to be provisioned
appropriately for the flow, and this is done by the QoS initiator appropriately for the flow, and the QoS initiator does this and
and controller(s), mapping their QoS control information to controller(s), mapping their QoS control information to technology-
technology-related QoS parameters and receiving indications about related QoS parameters and receiving indications about success or
success or failure in response. failure in response.
Now concentrating more on the overall end to end (multiple QoS Now concentrating more on the overall end to end (multiple QoS
domains) aspects, in particular: domains) aspects, in particular:
1. The QoS initiator need not be located at an end system, and the 1. The QoS initiator need not be located at an end system, and the
QoS controllers are not assumed to be located on the flow's data QoS controllers are not assumed to be located on the flow's data
path. However, they must be able to identify the ingress and egress path. However, they must be able to identify the ingress and egress
points for the flow path as it traverses the domain/subdomain. Any points for the flow path as it traverses the domain/subdomain. Any
signaling protocol must be able to find the appropriate QoS signaling protocol must be able to find the appropriate QoS
controller and carry this ingress/egress point information. controller and carry this ingress/egress point information.
2. We see the network at the level of domains/subdomains rather than 2. We see the network at the level of domains/subdomains rather than
individual routers (except in the special case that the domain individual routers (except in the special case that the domain
contains one link). Domains are assumed to be administrative contains one link). Domains are assumed to be administrative
entities, so security requirements apply to the signaling between entities, so security requirements apply to the signaling between
them. Subdomains are introduced to allow the fact a given QoS them. Subdomains are introduced to allow the fact a given QoS
provisioning mechanism may only be used within a part of a domain, provisioning mechanism may only be used within a part of a domain,
typically for a particular subnetwork technology boundary. typically for a particular subnetwork technology boundary.
Aggregation can also take place at subdomain boundaries. Aggregation can also take place at subdomain boundaries.
Requirements for QoS Signaling Protocols July 2002
3. Any domain may contain QoS administration functions (e.g. to do 3. Any domain may contain QoS administration functions (e.g. to do
with traffic engineering, admission control, policy and so on). with traffic engineering, admission control, policy and so on).
Brunner, et al. Informational [Page 7]
Requirements for QoS Signaling Protocols May 2002
These are assumed to interact with the QoS initiator and controllers These are assumed to interact with the QoS initiator and controllers
(and end systems) using standard mechanisms. (and end systems) using standard mechanisms.
4. The placement of the QoS initiators and QoS controllers is not 4. The placement of the QoS initiators and QoS controllers is not
fixed. Actually, there are two extreme cases: fixed. Actually, there are two extreme cases:
- Each router on the data path implements a QoS controller and QoS - Each router on the data path implements a QoS controller and QoS
initiator. initiator.
- Only the end systems incorporate a QoS controller and QoS - Only the end systems incorporate a QoS controller and QoS
initiator, which means the end systems need to have QoS provisioning initiator, which mean the end systems need to have QoS provisioning
capabilities. However this case does not seam to be realistic but capabilities. However this case does not seam to be realistic but
shows the flexible allocation of the controller and initiator shows the flexible allocation of the controller and initiator
function. function.
4 Assumptions and Exclusions 4 Assumptions and Exclusions
4.1 Assumptions and Non-Assumptions 4.1 Assumptions and Non-Assumptions
1. The NSIS signaling could run end to end, end to edge, or edge to 1. The NSIS signaling could run end to end, end to edge, or edge to
edge, or network-to-network ((between providers), depending on what edge, or network-to-network ((between providers), depending on what
skipping to change at line 405 skipping to change at page 10, line 41
other end of the network the signaling propagates. Although the other end of the network the signaling propagates. Although the
figures show QoS controllers at a very limited number of locations figures show QoS controllers at a very limited number of locations
in the network (e.g. at domain or subdomain borders, or even in the network (e.g. at domain or subdomain borders, or even
controlling a complete domain), this is only one possible case. In controlling a complete domain), this is only one possible case. In
general, we could expect QoS controllers to become more 'dense' general, we could expect QoS controllers to become more 'dense'
towards the edges of the network, but this is not a requirement. An towards the edges of the network, but this is not a requirement. An
overprovisioned domain might contain no QoS controllers at all (and overprovisioned domain might contain no QoS controllers at all (and
be NSIS transparent); at the other extreme, QoS controllers might be be NSIS transparent); at the other extreme, QoS controllers might be
placed at every router. In the latter case, QoS provisioning can be placed at every router. In the latter case, QoS provisioning can be
carried out in a local implementation-dependent way without further carried out in a local implementation-dependent way without further
signalling, whereas in the case of remote QoS controllers, a signaling, whereas in the case of remote QoS controllers, a
provisioning protocol might be needed to control the routers along provisioning protocol might be needed to control the routers along
the path. This provisioning protocol is then independent of the end the path. This provisioning protocol is then independent of the end
to end NSIS signalling. to end NSIS signaling.
2. We do not consider 'pure' end-to-end QoS signaling that is not 2. We do not consider 'pure' end-to-end QoS signaling that is not
interpreted anywhere within the network. Such signaling is an interpreted anywhere within the network. Such signaling is an
application-layer issue and IETF protocols such as SIP etc. can be application-layer issue and IETF protocols such as SIP etc. can be
used. used.
3. Where the signaling does cover several QoS domains or subdomains, 3. Where the signaling does cover several QoS domains or subdomains,
we do not exclude that different signaling protocols are used in we do not exclude that different signaling protocols are used in
each path segment. We only place requirements on the universality of each path segment. We only place requirements on the universality of
the QoS control information that is being transported. (The goals the QoS control information that is being transported. (The goals
here would be to allow the use of signaling protocols which are here would be to allow the use of signaling protocols, which are
matched to the characteristics of the portion of the network being matched to the characteristics of the portion of the network being
traversed.) Note that the outcome of NSIS work might result in traversed.) Note that the outcome of NSIS work might result in
various protocols or various flavors of the same protocol. This various protocols or various flavors of the same protocol. This
Requirements for QoS Signaling Protocols July 2002
implies the need for the translation of information into QoS domain implies the need for the translation of information into QoS domain
specific format as well. specific format as well.
Brunner, et al. Informational [Page 8]
Requirements for QoS Signaling Protocols May 2002
4. We assume that the service definitions a QoS initiator can ask 4. We assume that the service definitions a QoS initiator can ask
for are known in advance of the signaling protocol running. Service for are known in advance of the signaling protocol running. Service
definition includes QoS parameters, life-time of QoS guarantee etc. definition includes QoS parameters, lifetime of QoS guarantee etc.
There are many ways a service requester get to know about it. There There are many ways service requesters get to know about it. There
might be standardized services, the definition can be negotiated might be standardized services, the definition can be negotiated
together with a contract, the service definition is published at a together with a contract, the service definition is published at a
Web-page, etc. Web page, etc.
5. We assume that there are means for the discovery of NSIS entities 5. We assume that there are means for the discovery of NSIS entities
in order to know the signaling peers (solutions include static in order to know the signaling peers (solutions include static
configuration, automatically discovered, or implicitly runs over the configuration, automatically discovered, or implicitly runs over the
right nodes, etc.) right nodes, etc.) The discovery of the NSIS entities has security
implications that need to be addressed properly. These implications
largely depend on the chosen protocol. For some security mechanisms
(i.e. Kerberos, pre-shared secret) it is required to know the
identity of the other entity. Hence the discovery mechanism may
provide means to learn this identity, which is then later used to
retrieve the required keys and parameters.
6. NSIS assumes to operate with networks using standard ("normal")
L3 routing.
4.2 Exclusions 4.2 Exclusions
1. Development of specific mechanisms and algorithms for application 1. Development of specific mechanisms and algorithms for application
and transport layer adaptation are not considered, nor are the and transport layer adaptation are not considered, nor are the
protocols that would support it. protocols that would support it.
2. Specific mechanisms (APIs and so on) for interaction between 2. Specific mechanisms (APIs and so on) for interaction between
transport/applications and the network layer are not considered, transport/applications and the network layer are not considered,
except to clarify the requirements on the negotiation capabilities except to clarify the requirements on the negotiation capabilities
and information semantics that would be needed of the signaling and information semantics that would be needed of the signaling
protocol. The same applies to application adaptation mechanisms. protocol. The same applies to application adaptation mechanisms.
3. Specific mechanisms for QoS provisioning within a 3. Specific mechanisms for QoS provisioning within a
domain/subdomain are not considered. It should be possible to domain/subdomain are not considered. It should be possible to
exploit these mechanisms optimally within the end to end context. exploit these mechanisms optimally within the end to end context.
Consideration of how to do this might generate new requirements for Consideration of how to do this might generate new requirements for
NSIS however. For example, the information needed by an QoS NSIS however. For example, the information needed by a QoS
controller to manage a radio subnetwork needs to be provided by the controller to manage a radio subnetwork needs to be provided by the
NSIS solution. NSIS solution.
4. Specific mechanisms (APIs and so on) for interaction between the 4. Specific mechanisms (APIs and so on) for interaction between the
network layer and underlying QoS provisioning mechanisms are not network layer and underlying QoS provisioning mechanisms are not
considered. considered.
5. Interaction with QoS administration capabilities is not 5. Interaction with QoS administration capabilities is not
considered. Standard protocols should be used for this (e.g. COPS). considered. Standard protocols should be used for this (e.g. COPS).
This may imply requirements for the sort of information that should This may imply requirements for the sort of information that should
be exchanged between the NSIS network QoS entities. be exchanged between the NSIS network QoS entities.
6. Security issues related to multicasting are outside the scope of Requirements for QoS Signaling Protocols July 2002
the QoS signaling protocol.
Since multicasting is currently not an issue for the QoS protocol, 6. Security implications related to multicasting are outside the
security issues related to multicast are outside the scope. scope of the QoS signaling protocol.
Multicast security may additionally be an application issue that is
also outside the scope of the QoS protocol.
7. Protection of non-QoS signaling messages is outside the scope of 7. Protection of non-QoS signaling messages is outside the scope of
the QoS protocol the QoS protocol
Brunner, et al. Informational [Page 9] The protection of non-signaling messages (including data traffic
Requirements for QoS Signaling Protocols May 2002 following a reservation) is not directly considered by a signaling
protocol. The protection of data messages transmitted along the QoS
provisioned path is outside the scope of a signaling protocol.
Regarding data traffic there is an interaction with accounting
(metering) and edge routers might require packets to be integrity
protected to be able to securely assign incoming data traffic to a
particular user.
Security protection of data messages transmitted along the Additionally there might be an interaction with IPsec protected
established QoS path is outside the scope of the QoS protocol. These traffic experiencing QoS treatment and the established state created
security properties are likely to be application specific and may be due to signaling. One example of such an interaction is the different
provided by the corresponding application layer protocol. flow identification with and without IPsec protection.
Many security properties are likely to be application specific and
may be provided by the corresponding application layer protocol.
8. Service definitions and QoS classes are out of scope. Together 8. Service definitions and QoS classes are out of scope. Together
with the service definition any definition of service specific with the service definition any definition of service specific
parameters are not considered in this draft. Only the base NSIS parameters are not considered in this draft. Only the base NSIS
signaling protocol for transporting the QoS/service information are signaling protocol for transporting the QoS/service information are
handled. handled.
9. Similarly, specific methods, protocols, and ways to express QoS 9. Similarly, specific methods, protocols, and ways to express QoS
information in the Application/Session level are not considered information in the Application/Session level are not considered
(e.g., SDP, SIP, RTSP, etc.). (e.g., SDP, SIP, RTSP, etc.).
10. The specification of any extensions needed to signal QoS 10. The specification of any extensions needed to signal QoS
information via application level protocols (e.g. SDP(ng)), and the information via application level protocols (e.g. SDP(ng)), and the
mapping on NSIS information are considered outside of the scope of mapping on NSIS information are considered outside of the scope of
NSIS working group, as this work is in the direct scope of other NSIS working group, as this work is in the direct scope of other
IETF working groups (e.g. MMUSIC). IETF working groups (e.g. MMUSIC).
11. Handoff decision and trigger sources: An NSIS protocol is not
used to trigger handoffs in mobile IP, nor is it used to decide
whether to handoff or not. As soon as or in some situation even
before a handoff happened, an NSIS protocol might be used for
signaling for QoS again. However, NSIS must interwork with several
protocols for mobility management.
12. QoS monitoring is out of scope. It is heavily dependent on the
type of the application and or transport service, and in what
scenario it is used.
5 Requirements 5 Requirements
Requirements for QoS Signaling Protocols July 2002
This section defines more detailed requirements for a QoS signaling This section defines more detailed requirements for a QoS signaling
solution, derived from consideration of the use cases/scenarios, and solution, derived from consideration of the use cases/scenarios, and
respecting the framework, scoping assumptions, and terminology respecting the framework, scoping assumptions, and terminology
considered earlier. The requirements are in subsections, grouped considered earlier. The requirements are in subsections, grouped
roughly according to general technical aspects: architecture and roughly according to general technical aspects: architecture and
design goals, topology issues, QoS parameters, performance, design goals, topology issues, QoS parameters, performance,
security, information, and flexibility. security, information, and flexibility.
Two general (and potentially contradictory) goals for the solution Two general (and potentially contradictory) goals for the solution
skipping to change at line 538 skipping to change at page 13, line 36
Find in Section 6 the MUSTs, SHOULDs, and MAYs Find in Section 6 the MUSTs, SHOULDs, and MAYs
5.1 Architecture and Design Goals 5.1 Architecture and Design Goals
This section contains requirements related to desirable overall This section contains requirements related to desirable overall
characteristics of a solution, e.g. enabling flexibility, or characteristics of a solution, e.g. enabling flexibility, or
independence of parts of the framework. independence of parts of the framework.
5.1.1 Applicability for different QoS technologies. 5.1.1 Applicability for different QoS technologies.
Brunner, et al. Informational [Page 10]
Requirements for QoS Signaling Protocols May 2002
The QoS signaling protocol must work with various QoS technologies. The QoS signaling protocol must work with various QoS technologies.
The information exchanged over the signaling protocol must be in The information exchanged over the signaling protocol must be in
such detail and quantity that it is useful for various QoS such detail and quantity that it is useful for various QoS
technologies. technologies.
5.1.2 Resource availability information on request 5.1.2 Resource availability information on request
In some scenarios, e.g., the mobile terminal scenario, it is In some scenarios, e.g., the mobile terminal scenario, it is
required to query, whether resources are available, without required to query, whether resources are available, without
performing a reservation on the resource. One solution might be a performing a reservation on the resource. One solution might be a
skipping to change at line 564 skipping to change at page 13, line 59
5.1.3 Modularity 5.1.3 Modularity
A modular design allows for more lightweight implementations, if A modular design allows for more lightweight implementations, if
fewer features are needed. Mutually exclusive solutions are fewer features are needed. Mutually exclusive solutions are
supported. Examples for modularity: supported. Examples for modularity:
- Work over any kind of network (narrowband / broadband, error-prone - Work over any kind of network (narrowband / broadband, error-prone
/ reliable...) - This implies low bandwidth signaling and redundant / reliable...) - This implies low bandwidth signaling and redundant
information must be supported if necessary. information must be supported if necessary.
- In case QoS requirements are soft (e.g. banking transactions,
gaming), fast and lightweight signaling (e.g., not more than one
round-trip time)
- Uni- and bi-directional reservations are possible - Uni- and bi-directional reservations are possible
Requirements for QoS Signaling Protocols July 2002
- Extensible in the future with different add-ons for certain
environments or scenarios
5.1.4 Decoupling of protocol and information it is carrying 5.1.4 Decoupling of protocol and information it is carrying
The signaling protocol(s) used must be clearly separated from the The signaling protocol(s) used must be clearly separated from the
QoS control information being transported. This provides for the QoS control information being transported. This provides for the
independent development of these two aspects of the solution, and independent development of these two aspects of the solution, and
allows for this control information to be carried within other allows for this control information to be carried within other
protocols, including application layer ones, existing ones or those protocols, including application layer ones, existing ones or those
being developed in the future. The gained flexibility in the being developed in the future. The gained flexibility in the
information transported allows for the applicability of the same information transported allows for the applicability of the same
skipping to change at line 593 skipping to change at page 14, line 32
5.1.5 Reuse of existing QoS provisioning 5.1.5 Reuse of existing QoS provisioning
Reuse existing QoS functions and protocols for QoS provisioning Reuse existing QoS functions and protocols for QoS provisioning
within a domain/subdomain unchanged. (Motivation: 'Don't re-invent within a domain/subdomain unchanged. (Motivation: 'Don't re-invent
the wheel'.) the wheel'.)
5.1.6 Independence of signaling and provisioning paradigm 5.1.6 Independence of signaling and provisioning paradigm
The QoS signaling should be independent of the paradigm and The QoS signaling should be independent of the paradigm and
mechanism of QoS provisioning. The independence allows for using the mechanism of QoS provisioning. The independence allows for using the
NSIS protocol together with various QoS technologies. NSIS protocol together with various QoS technologies in various
scenarios.
Brunner, et al. Informational [Page 11]
Requirements for QoS Signaling Protocols May 2002
5.2 Signaling Flows 5.2 Signaling Flows
This section contains requirements related to the possible signaling This section contains requirements related to the possible signaling
flows that should be supported, e.g. over what parts of the flow flows that should be supported, e.g. over what parts of the flow
path, between what entities (end-systems, routers, middleboxes, path, between what entities (end-systems, routers, middleboxes,
management systems), in which direction. management systems), in which direction.
5.2.1 Free placement of QoS Initiator and QoS Controllers functions 5.2.1 Free placement of QoS Initiator and QoS Controllers functions
The protocol(s) must work in various scenarios such as host-to- The protocol must work in various scenarios such as host-to-network-
network-to-host, edge-to-edge, (e.g., just within one providers to-host, edge-to-edge, (e.g., just within one providers domain),
domain), user-to-network (from end system into the network, ending, user-to-network (from end system into the network, ending, e.g., at
e.g., at the entry to the network and vice versa), network-to- the entry to the network and vice versa), network-to-network (e.g.,
network (e.g., between providers). between providers).
Placing the QoS controller and initiator functions at different Placing the QoS controller and initiator functions at different
locations allows for various scenarios to work with the same or locations allows for various scenarios to work with the same or
similar protocols. similar protocols.
5.2.2 No constraint of the QoS signaling and QoS Controllers to be in 5.2.2 No constraint of the QoS signaling and QoS Controllers to be in
the data path. the data path.
Requirements for QoS Signaling Protocols July 2002
There is a set of scenarios, where QoS signaling is not on the data There is a set of scenarios, where QoS signaling is not on the data
path. The QoS Controller being in the data path is one extreme case path. The QoS Controller being in the data path is one extreme case
and useful in certain cases. and useful in certain cases.
There are going to be cases where a centralized entity will take a There are going to be cases where a centralized entity will take a
decision about QoS requests. In this case, there's no question there decision about QoS requests. In this case, there is no need to have
is no need to have data follow the signalling path. the data follow the signaling path.
There are going to be cases wiout a centralized entity managing There are going to be cases without a centralized entity managing
resources and the signaling will be used as a tool for resource resources and the signaling will be used as a tool for resource
management. For various reasons (such as efficient use of expensive management. For various reasons (such as efficient use of expensive
bandwidth), one will want to have fine-grained, fast, and very bandwidth), one will want to have fine-grained, fast, and very
dynamic control of the resources in the network. - dynamic control of the resources in the network.
There are going to be cases where there will be neither signaling There are going to be cases where there will be neither signaling
nor a centralized entity (overprovisioning). Nothing has to be done nor a centralized entity (overprovisioning). Nothing has to be done
anyway. anyway.
One can capture the requirement with the following wording: If one One can capture the requirement with the following, different
views the domain with a QoS technology as a virtual router then NSIS wording: If one views the domain with a QoS technology as a virtual
signaling used between those virtual routers must follow the same router then NSIS signaling used between those virtual routers must
path as the data. follow the same path as the data.
Routing the signaling protocol along an independent path is desired Routing the signaling protocol along an independent path is desired
by network operators/designers. Ideally, the capability to route the by network operators/designers. Ideally, the capability to route the
protocol along an independent path would give the network protocol along an independent path would give the network
designer/operator the option to manage bandwidth utilization through designer/operator the option to manage bandwidth utilization through
the topology. the topology.
There are other possibilities as well. An NSIS protocol must accept There are other possibilities as well. An NSIS protocol must accept
all of these possibilities. all of these possibilities.
Brunner, et al. Informational [Page 12]
Requirements for QoS Signaling Protocols May 2002
5.2.3 Concealment of topology and technology information 5.2.3 Concealment of topology and technology information
The QoS protocol should allow hiding the internal structure of a QoS The QoS protocol should allow for hiding the internal structure of a
domain from end-nodes and from other networks. Hence an adversary QoS domain from end-nodes and from other networks. Hence an
should not be able to learn the internal structure of a network with adversary should not be able to learn the internal structure of a
the help of the QoS protocol. network with the help of the QoS protocol.
In various scenarios, topology information should be hidden for In various scenarios, topology information should be hidden for
various reasons. From a business point of view, some administrations various reasons. From a business point of view, some administrations
don't want to reveal the topology and technology used. don't want to reveal the topology and technology used.
5.2.4 Optional transparency of QoS signaling to network 5.2.4 Optional transparency of QoS signaling to network
It should be possible that the QoS signaling for some flows traverse It should be possible that the QoS signaling for some flows traverse
path segments transparently, i.e., without interpretation at QoS path segments transparently, i.e., without interpretation at QoS
controllers within the network. An example would be a subdomain controllers within the network. An example would be a subdomain
within a core network, which only interpreted signaling for within a core network, which only interpreted signaling for
aggregates established at the domain edge, with the flow-related aggregates established at the domain edge, with the flow-related
signaling passing transparently through it. signaling passing transparently through it.
Requirements for QoS Signaling Protocols July 2002
In other words, NSIS needs to work in hierarchical scenarios, where
big pipes/trunks are setup using NSIS signaling, but also flows
which run within that big pipe/trunk are setup using NSIS.
5.3 Additional information beyond signaling of QoS information 5.3 Additional information beyond signaling of QoS information
This section contains the desired signaling (messages) for other This section contains the desired signaling (messages) for other
purposes other than that for conveying QoS parameters. purposes other than that for conveying QoS parameters.
5.3.1 Explicit release of resources 5.3.1 Explicit release of resources
When a QoS reservation is no longer necessary, e.g. because the When a QoS reservation is no longer necessary, e.g. because the
application terminates, or because a mobile host experienced a hand- application terminates, or because a mobile host experienced a hand-
off, it must be possible to explicitly release resources. off, it must be possible to explicitly release resources. In general
explicit release enhances the overall network utilization.
5.3.2 Possibility for automatic release of resources after failure 5.3.2 Possibility for automatic release of resources after failure
When the QoS Initiator goes down, the resources it requested in the When the QoS Initiator goes down, the resources it requested in the
network should be released, since they will no longer be necessary. network should be released, since they will no longer be necessary.
After detection of a failure in the network, any QoS After detection of a failure in the network, any QoS
controller/initiator must be able to release a reservation it is controller/initiator must be able to release a reservation it is
involved in. For example, this may require signaling of the "Release involved in. For example, this may require signaling of the "Release
after Failure" message upstream as well as downstream, or soft state after Failure" message upstream as well as downstream, or soft state
timing out of reservations. timing out of reservations.
The goal is to prevent stale state within the network and adds
robustness to the operation of NSIS. So in other words, an NSIS
signaling protocol must provide means for an NSIS signaling unit to
discover and remove local stale state.
Note that this might need to work together with a notification Note that this might need to work together with a notification
mechanism. mechanism.
5.3.3 Possibility for automatic re-setup of resources after recovery 5.3.3 Prompt notification of QoS violation in case of error/failure to
In case of a failure, the reservation can get setup again
automatically. It enables sort of a persistent reservation, if the
QoS Initiator requests it. In scenarios where the reservations are
Brunner, et al. Informational [Page 13]
Requirements for QoS Signaling Protocols May 2002
on a longer time scale, this could make sense to reduce the
signaling load in case of failure and recovery.
5.3.4 Prompt notification of QoS violation in case of error/failure to
QoS Initiator and QoS Controllers QoS Initiator and QoS Controllers
QoS Controllers should be able to notify the QoS Initiator, if there QoS Controllers should be able to notify the QoS Initiator, if there
is an error inside the network. There are two types of network is an error inside the network. There are two types of network
errors: errors:
Recoverable errors: This type error can be locally repaired by the Recoverable errors: the network nodes can locally repair this type
network nodes. The network nodes do not have to notify the users of error. The network nodes do not have to notify the users of the
the error immediately. This is a condition when the danger of error immediately. This is a condition when the danger of
degradation (or actual short term degradation) of the provided QoS degradation (or actual short term degradation) of the provided QoS
was overcome by the network (QoS controller) itself. was overcome by the network (QoS controller) itself.
Unrecoverable errors: the network nodes cannot handle this type of Unrecoverable errors: the network nodes cannot handle this type of
error, and have to notify the users as soon as possible. error, and have to notify the users as soon as possible.
5.3.5 Feedback about success of request for QoS guarantees 5.3.4 Feedback about success of request for QoS guarantees
Requirements for QoS Signaling Protocols July 2002
A request for QoS must be answered at least with yes or no. However, A request for QoS must be answered at least with yes or no. However,
it might be useful in case of a negative answer to also get a it might be useful in case of a negative answer to also get a
description of what might be the QoS one can successfully request description of what might be the QoS one can successfully request
etc. So it might be useful to include an opaque element into the etc. So it might be useful to include an opaque element into the
answer. The element heavily depends on the service requested. answer. The element heavily depends on the service requested.
5.3.6 Allow local QoS information exchange between nodes of the same 5.3.5 Allow local QoS information exchange between nodes of the same
administrative domain administrative domain
The QoS signaling protocol must be able to exchange local QoS The QoS signaling protocol must be able to exchange local QoS
information between QoS controllers located within one single information between QoS controllers located within one single
domain. Local QoS information might, for example, be IP addresses, domain. Local QoS information might, for example, be IP addresses,
severe congestion notification, notification of successful or severe congestion notification, notification of successful or
erroneous processing of QoS signaling messages. erroneous processing of QoS signaling messages.
In some cases, the NSIS QoS signalling protocol may carry In some cases, the NSIS QoS signaling protocol may carry
identification of the QoS controllers located at the boundaries of a identification of the QoS controllers located at the boundaries of a
domain. However, the identification of edge should not be visible to domain. However, the identification of edge should not be visible to
the end host (QoS initiator) and only applies within one QoS the end host (QoS initiator) and only applies within one QoS
administrative domain. administrative domain.
5.4 Layering 5.4 Layering
This section contains requirements related to the way the signaling This section contains requirements related to the way the signaling
being considered interacts with upper layer functions (users, being considered interacts with upper layer functions (users,
applications, and QoS administration), and lower layer QoS applications, and QoS administration), and lower layer QoS
technologies. technologies.
5.4.1 The signaling protocol and QoS control information should be 5.4.1 The signaling protocol and QoS control information should be
application independent. application independent.
Brunner, et al. Informational [Page 14]
Requirements for QoS Signaling Protocols May 2002
However, opaque application information might get transported in the However, opaque application information might get transported in the
signaling message, without being handled in the network. Development signaling message, without being handled in the network. Development
and deployment of new applications should be possible without and deployment of new applications should be possible without
impacting the network infrastructure. Additionally, QoS protocols impacting the network infrastructure. Additionally, QoS protocols
are expected to conform to the Internet principles. are expected to conform to the Internet principles.
5.5 QoS Control Information 5.5 QoS Control Information
This section contains requirements related to the QoS control This section contains requirements related to the QoS control
information that needs to be exchanged. information that needs to be exchanged.
skipping to change at line 785 skipping to change at page 17, line 58
5.5.1 Mutability information on parameters 5.5.1 Mutability information on parameters
It should be possible for the initiator to control the mutability of It should be possible for the initiator to control the mutability of
the QSC information. This prevents from being changed in a non- the QSC information. This prevents from being changed in a non-
recoverable way. The initiator should be able to control what is recoverable way. The initiator should be able to control what is
requested end to end, without the request being gradually mutated as requested end to end, without the request being gradually mutated as
it passes through a sequence of domains. This implies that in case it passes through a sequence of domains. This implies that in case
of changes made on the parameters, the original requested ones must of changes made on the parameters, the original requested ones must
still be available. still be available.
Note that we do not require anything about particular QoS paramters Note that we do not require anything about particular QoS parameters
being changed. being changed.
Requirements for QoS Signaling Protocols July 2002
Additionally, note that a provider or that particular QoS requested,
can still influence the QoS provisioning but in the signaling
message the request should stay the same.
5.5.2 Possibility to add and remove local domain information 5.5.2 Possibility to add and remove local domain information
It should be possible for the QoS control functions to add and It should be possible for the QoS control functions to add and
remove local scope elements. E.g., at the entrance to a QoS domain remove local scope elements. E.g., at the entrance to a QoS domain
domain-specific information is added, which is used in this domain domain-specific information is added, which is used in this domain
only, and the information is removed again when a signaling message only, and the information is removed again when a signaling message
leaves the domain. The motivation is in the economy of re-use the leaves the domain. The motivation is in the economy of re-use the
protocol for domain internal signaling of various information. Where protocol for domain internal signaling of various information
additional information is needed for QoS control within a particular pieces. Where additional information is needed for QoS control
domain, it should be possible to carry this at the same time as the within a particular domain, it should be possible to carry this at
'end to end' information.) the same time as the 'end to end' information.)
5.5.3 Independence of reservation identifier 5.5.3 Independence of reservation identifier
A reservation identifier must be used, which is independent of the A reservation identifier must be used, which is independent of the
flow identifier, the IP address of the QoS Initiator, and the flow flow identifier, the IP address of the QoS Initiator, and the flow
end-points. Various scenarios in the mobility area require this end-points. Various scenarios in the mobility area require this
independence because flows resulting from handoff might have changed independence because flows resulting from handoff might have changed
end-points etc. but still have the same QoS requirement. end-points etc. but still have the same QoS requirement.
5.5.4 Seamless modification of already reserved QoS 5.5.4 Seamless modification of already reserved QoS
In many case, the reservation needs to be updated (up or downgrade). In many case, the reservation needs to be updated (up or downgrade).
This must happen seamlessly without service interruption. At least This must happen seamlessly without service interruption. At least
the signaling protocol must allow for it, even if some data path the signaling protocol must allow for it, even if some data path
elements might not be capable of doing so. elements might not be capable of doing so.
5.5.5 Signaling must support quantitative, qualitative, and relative 5.5.5 Grouping of signaling for several microflows
QoS specifications
Brunner, et al. Informational [Page 15] NSIS may group signaling information for several microflow into one
Requirements for QoS Signaling Protocols May 2002 signaling message. The goal of this is the optimization in terms of
setup delay, which can happen in parallel. This helps applications
requesting several flows at once. Also potential refreshes (in case
of a soft state solution) might profit of grouping.
However, the network must not know that a relationship between the
grouped flows exists. Nor is there any transactional semantic
allowed. It is only meant for optimization purposes and each
reservation is handled separately from each other.
5.6 Performance 5.6 Performance
This section discusses performance requirements and evaluation This section discusses performance requirements and evaluation
criteria and the way in which these could and should be traded off criteria and the way in which these could and should be traded off
against each other in various parts of the solution. against each other in various parts of the solution.
Scalability is a must anyway. However, depending on the scenario the Scalability is a must anyway. However, depending on the scenario the
question to which extends the protocol must be scalable. question to which extends the protocol must be scalable.
Requirements for QoS Signaling Protocols July 2002
5.6.1 Scalability in the number of messages received by a signaling 5.6.1 Scalability in the number of messages received by a signaling
communication partner (QoS initiator and controller) communication partner (QoS initiator and controller)
5.6.2 Scalability in number of hand-offs 5.6.2 Scalability in number of hand-offs
5.6.3 Scalability in the number of interactions for setting up a 5.6.3 Scalability in the number of interactions for setting up a
reservation reservation
5.6.4 Scalability in the number of state per entity (QoS initiators and 5.6.4 Scalability in the number of state per entity (QoS initiators and
QoS controllers) QoS controllers)
skipping to change at line 876 skipping to change at page 19, line 53
signaling intensity) on devices where it is needed. One of the signaling intensity) on devices where it is needed. One of the
reasons is that the protocol handling should have a minimal impact reasons is that the protocol handling should have a minimal impact
on interior (core) nodes. on interior (core) nodes.
This can be achieved by many different methods. Examples, and this This can be achieved by many different methods. Examples, and this
are only examples, include message aggregation, by ignoring are only examples, include message aggregation, by ignoring
signaling message, header compression, or minimizing functionality. signaling message, header compression, or minimizing functionality.
The framework may choose any method as long as the requirement is The framework may choose any method as long as the requirement is
met. met.
Brunner, et al. Informational [Page 16]
Requirements for QoS Signaling Protocols May 2002
5.6.9 Highest possible network utilization 5.6.9 Highest possible network utilization
There are networking environments that require high network There are networking environments that require high network
utilization for various reasons, and the signaling protocol should utilization for various reasons, and the signaling protocol should
to its best ability support high resource utilization while to its best ability support high resource utilization while
maintaining appropriate QoS. maintaining appropriate QoS.
Requirements for QoS Signaling Protocols July 2002
In networks where resources are very expensive (as is the case for In networks where resources are very expensive (as is the case for
many wireless networks), efficient network utilization is of many wireless networks), efficient network utilization is of
critical financial importance. On the other hand there are other critical financial importance. On the other hand there are other
parts of the network where high utilization is not required. parts of the network where high utilization is not required.
5.7 Flexibility 5.7 Flexibility
This section lists the various ways the protocol can flexibly be This section lists the various ways the protocol can flexibly be
employed. employed.
5.7.1 Aggregation capability, including the capability to select and 5.7.1 Aggregation capability, including the capability to select and
change the level of aggregation. change the level of aggregation.
5.7.2 Flexibility in the placement of the QoS initiator 5.7.2 Flexibility in the placement of the QoS initiator
It might be the sender or the receiver of content. But also network- It might be the sender or the receiver of content. But also network-
initiated reservations are required in various scenarios. initiated reservations are required in various scenarios such as
PSTN gateways, some VPNs, mobility.
5.7.3 Flexibility in the initiation of re-negotiation (QoS change 5.7.3 Flexibility in the initiation of re-negotiation (QoS change
requests) requests)
Again the sender or the receiver of content might initiate a re- Again the sender or the receiver of content might initiate a re-
negotiation due to various reasons, such as local resource shortage negotiation due to various reasons, such as local resource shortage
(CPU, memory on end-system) or a user changed application (CPU, memory on end-system) or a user changed application
preference/profiles. But also network-initiated re-negotiation is preference/profiles. But also network-initiated re-negotiation is
required in cases, where the network is not able to further required in cases, where the network is not able to further
guarantee resources etc. guarantee resources etc.
5.7.4 Uni / bi-directional reservation 5.7.4 Uni / bi-directional reservation
Both uni-directonal as well as bi-direction reservations must be Both unidirectional as well as bi-direction reservations must be
possible. possible. With bi-directional reservations we mean here reservations
having the same end-points. But the path in the two directions does
not need to be the same.
5.8 Security The goal of a bi-directional reservation is mainly an optimization
in terms of setup delay. There is no requirements on constrains such
as use the same data path etc.
This section discusses security-related requirements. First a list 5.8 Security
of security threats is given.
5.8.1 The QoS protocol must provide strong authentication This section discusses security-related requirements. For a
discussion of security threats see [12].
A QoS protocol must make provision for enabling various entities to 5.8.1 Authentication of signaling requests
Brunner, et al. Informational [Page 17] A signaling protocol must make provision for enabling various
Requirements for QoS Signaling Protocols May 2002 entities to be authenticated against each other using strong
authentication mechanisms. The term strong authentication points to
the fact that weak plain-text password mechanisms must not be used
for authentication.
be authenticated against each other using data origin and/or entity Requirements for QoS Signaling Protocols July 2002
authentication. The QoS protocol must enable mutual authentication
between the two communicating entities. The term strong
authentication points to the fact that weak plain-text password
mechanisms must not be used for authentication.
5.8.2 The QoS protocol must provide means to authorize resource 5.8.2 Resource Authorization
requests
This requirement demands a hook to interact with a policy entity to The signaling protocol must provide means to authorize resource
request authorization data. This allows an authenticated entity to requests. This requirement demands a hook to interact with a policy
be associated with authorization data and to verify the resource entity to request authorization data. This allows an authenticated
request. Authorization prevents reservations by unauthorized entity to be associated with authorization data and to verify the
resource request. Authorization prevents reservations by unauthorized
entities, reservations violating policies, theft of service and entities, reservations violating policies, theft of service and
additionally limits denial of service attacks against parts of the additionally limits denial of service attacks against parts of the
network or the entire network. Additionally it might be helpful to network or the entire network caused by unrestricted reservations.
provide some means to inform other protocols of participating nodes Additionally it might be helpful to provide some means to inform
within the same administrative domain about a previous successful other protocols of participating nodes within the same administrative
authorization event. domain about a previous successful authorization event.
5.8.3 The QoS signaling messages must provide integrity protection. 5.8.3 Integrity protection
The integrity protection of the transmitted signaling messages The signaling protocol must provide means to protect the message
prevent an adversary from modifying parts of the QoS signaling payloads against modifications. Integrity protection prevents an
message and from mounting denial of service attacks against network adversary from modifying with parts of the signaling message and from
elements participating in the QoS protocol. mounting denial of service or theft of service type of attacks
against network elements participating in the protocol execution.
5.8.4 The QoS signaling messages must be replay protected. 5.8.4 Replay protection
To prevent replay of previous signaling messages the QoS protocol To prevent replay of previous signaling messages the signaling
must provide means to detect old messages. A solution must cover protocol must provide means to detect old i.e. already transmitted
issues of synchronization problems in the case of a restart or a signaling messages. A solution must cover issues of synchronization
crash of a participating network element. The use of replay problems in the case of a restart or a crash of a participating
mechanism apart from sequence numbers should be investigated. network element. The use of replay mechanism apart from sequence
numbers should be investigated.
5.8.5 The QoS signaling protocol must allow for hop-by-hop security. 5.8.5 Hop-by-hop security
Hop-by-Hop security is a well known and proven concept in QoS Hop-by-Hop security is a well known and proven concept in Quality-of-
protocols that allows intermediate nodes that actively participate Service and other signaling protocols that allows intermediate nodes
in the QoS protocol to modify the messages as required by the QoS that actively participate in the protocol to modify the messages as
processing. Note that this requirement does not exclude end-to-end it is required by processing rule. Note that this requirement does
or network-to-network security of a QoS reservation request. End-to- not exclude end-to-end or network-to-network security of a signaling
end security between the initiator and the responder may be used to message. End-to-end security between the initiator and the responder
provide protection of non-mutable data fields. Network-to-network may be used to provide protection of non-mutable data fields.
security refers to the protection of messages over various hops but Network-to-network security refers to the protection of messages over
not in an end-to-end manner i.e. protected over a particular various hops but not in an end-to-end manner i.e. protected over a
network. particular network.
5.8.6 The QoS protocol should allow identity confidentiality and 5.8.6 Identity confidentiality and location privacy
location privacy.
Identity confidentiality enables privacy and avoids profiling of Identity confidentiality enables privacy and avoids profiling of
entities by adversary eavesdropping the signaling traffic along the entities by adversary eavesdropping the signaling traffic along the
path. The identity used in the process of authentication may also be path. The identity used in the process of authentication may also be
hidden to a limited extent from a network to which the initiator is
attached. It is however required that the identity provides enough
information for the nodes in the access network to collect accounting
data.
Brunner, et al. Informational [Page 18] Requirements for QoS Signaling Protocols July 2002
Requirements for QoS Signaling Protocols May 2002
hidden to a limited extent from a network to which the initiator is Location privacy is an issue for the initiator who triggers the
attached. It is however required that the identity provide enough signaling protocol. In some scenarios the initiator may not be
information for the access network to collect accounting data. willing to reveal location information to the responder as part the
Location privacy is an issue for the initiator who triggers the QoS signaling procedure.
protocol. In some scenarios the initiator may not be willing to The signaling protocol should provide means to protect the identity
reveal location information to the responder. confidentiality and as far as possible location privacy.
5.8.7 The QoS protocol should prevent denial-of-service attacks against 5.8.7 Denial-of-service attacks
signaling entities.
To effectively prevent denial-of-service attacks the QoS protocol To effectively prevent denial-of-service attacks it is necessary that
and the used security mechanisms should not force to do heavy the used security and protocol mechanisms should not require the
computation to verify a resource request prior authenticating the execution of heavy computation to verify a resource request prior
requesting entity. Additionally the QoS protocol and the used authenticating the requesting entity. Additionally the signaling
security mechanisms should not require large resource consumption protocol and the used security mechanisms should not require large
(for example main memory or other additional message exchanges) resource consumption (for example main memory or other additional
before a successful authentication was done. message exchanges) before a successful authentication was done. A
signaling protocol should provide prevention of DoS attacks.
5.8.8 The QoS protocol should support confidentiality of signaling 5.8.8 Confidentiality of signaling messages
messages.
Based on the signaling information exchanged between nodes Based on the signaling information exchanged between nodes
participating in the QoS protocol an adversary may learn both the participating in the signaling protocol an adversary may learn both
identities and the content of the QoS messages. To prevent this from the identities and the content of the signaling messages. To prevent
happening, confidentiality of the QoS requests in a hop-by-hop this from happening, confidentiality of the signaling message in a
manner should be provided. Note that hop-by-hop is always required hop-by-hop manner may be provided. Note that the protection can be
whenever entities actively participating in the protocol must be provided on a hop-by-hop basis for most message payloads since it is
able to read and eventually modify the content of the QoS messages. required that entities which actively participating in the signaling
This does not exclude the case where one or more network elements protocol must be able to read and eventually modify the content of
are not required to read the information of the transmitted QoS the signaling messages.
messages.
5.8.9 The QoS protocol should provide hooks to interact with protocols 5.8.9 Ownership of a reservation
that allow the negotiation of authentication and key management
protocols.
The negotiation of an authentication and key management protocols When existing reservations have to be modified then there is a need
within the QoS protocol is outside the scope of the QoS protocol. to use a reservation identifier to uniquely identify the established
This requirement originates from the fact that more than one key state. A signaling protocol must provide the appropriate security
management protocol may be used to provide security associations. So protection to prevent other entities to modify state without having
both entities must be capable to use the same protocol which may be the proper ownership.
difficult in a mobile environment with different requirements and
different protocols. The goal of such a negotiation step is to
determine which authentication and key management protocol to use is
executed prior to the execution of the chosen key management
protocol. The used key management protocol must however be able to
create a security association that matches with the one used in the
QoS protocol. A QoS protocol should however provide a way to
interact with these negotiation protocols.
5.8.10 The QoS protocol should provide means to interact with key 5.8.10 Hooks with Authentication and Key Agreement protocols
management protocols
Brunner, et al. Informational [Page 19] This requirement covers two subsequent steps before a signaling
Requirements for QoS Signaling Protocols May 2002 protocol is executed and the required hooks. First there is a need to
agree on a specific authentication protocol. Later this protocol is
executed and provides authentication and establishes the desired
security associations. Using these security associations it is then
possible to exchange secured signaling messages.
The signaling protocol should provide hooks to interact with
protocols that allow the negotiation of authentication and key
agreement protocols. Although the negotiation of an authentication
and key management protocol within the signaling protocol may be
outside the scope it is still required to trigger this exchange in
case that no such security association is available.
Requirements for QoS Signaling Protocols July 2002
This requirement originates from the fact that more than one key
management protocol may be used to provide a security association for
the signaling protocol. Hence the communicating entities must be
capable to agree on a specific authentication. The selected
authentication and key agreement protocol must however be able to
create a security association that can be used within the signaling
protocol.
Key management protocols typically require a larger number of Key management protocols typically require a larger number of
messages to be transmitted to allow a session key and the messages to be transmitted to allow a session key and the
corresponding security association to be derived. To avoid the corresponding security association to be derived. To avoid the
complex issue of mapping individual authentication and key complex issue of embedding individual authentication and key
management protocols to a QoS protocol such a protocol is outside agreement protocols into a specific signaling protocol it is required
the scope of the QoS protocol. Although the key management protocol that most of these protocols are executed independently (prior to the
may be independent there must be a way for the QoS protocol to signaling protocol) and although the key management protocol may be
exploit existing security associations to avoid executing a separate independent there must be a way for the signaling protocol to access
key management protocol (or instance of the same protocol) for and use available (i.e. already established) security associations to
protocols that closely operate together. If no such security avoid executing a separate key management protocol (or instance of
association exists then there should be means for the QoS protocol the same protocol) for protocols that closely operate together. If no
to trigger a key management protocol to dynamically create the such security association exists then there should be means for the
required security associations. signaling protocol to dynamically trigger such a protocol.
5.9 Mobility 5.9 Mobility
5.9.1 Allow efficient QoS re-establishment after handover 5.9.1 Allow efficient QoS re-establishment after handover
Handover is an essential function in wireless networks. After Handover is an essential function in wireless networks. After
handover, QoS may need to be completely or partially re-established handover, QoS may need to be completely or partially re-established
due to route changes. The re-establishment may be requested by the due to route changes. The re-establishment may be requested by the
mobile node itself or triggered by the access point that the mobile mobile node itself or triggered by the access point that the mobile
node is attached to. In the first case, the QoS signalling should node is attached to. In the first case, the QoS signaling should
allow efficient QoS re-establishment after handover. Re- allow efficient QoS re-establishment after handover. Re-
establishment of QoS after handover should be as quick as possible establishment of QoS after handover should be as quick as possible
so that the mobile node does not experience service interruption or so that the mobile node does not experience service interruption or
QoS degradation. The re-establishment should be localized, and not QoS degradation. The re-establishment should be localized, and not
require end-to-end signalling, if possible. require end-to-end signaling, if possible.
TBD
5.10 Interworking with other protocols and techniques 5.10 Interworking with other protocols and techniques
Hooks must be provided to enable efficient interworking between Hooks must be provided to enable efficient interworking between
various protocols and techniques including: various protocols and techniques including:
5.10.1 Interworking with IP tunneling 5.10.1 Interworking with IP tunneling
IP tunneling for various applications must be supported. More IP tunneling for various applications must be supported. More
specifically tunneling for IPSec tunnels are of importance. This specifically tunneling for IPSec tunnels are of importance. This
mainly impacts the identification of flows. Additionally, care needs mainly impacts the identification of flows. Using IPsec parts of
to be taken using IPSec for signaling message. information for flow identification (e.g. transport protocol
information), this information is not accessible for classification
etc.
5.10.2 The solution should not constrain either to IPv4 or IPv6 5.10.2 The solution should not constrain either to IPv4 or IPv6
Requirements for QoS Signaling Protocols July 2002
5.10.3 Independence from charging model 5.10.3 Independence from charging model
Signaling must not be constrained by charging models or the charging Signaling must not be constrained by charging models or the charging
infrastructure used. However, the end-system should be able to query infrastructure used.
current pay statistics and to specify user cost functions.
5.10.4 The QoS protocol should provide hooks for AAA protocols
Brunner, et al. Informational [Page 20] 5.10.4 Hooks for AAA protocols
Requirements for QoS Signaling Protocols May 2002
The security mechanism should be developed with respect to be able The security mechanism should be developed with respect to be able
to collect usage records from one or more network elements. to collect usage records from one or more network elements.
5.10.5 Interworking with seamless handoff protocols
An NSIS protocol should interwork with seamless handoff protocols
such as context transfer and candidate access router (CAR)
discovery. The goal to achieve is that signaling for QoS works fast
enough in case of a handoff, where that protocols might help in one
way or the other.
5.10.6 Interworking with non-traditional routing
NSIS assumes traditional routing, but networks, which do non-
traditional L3 routing, should not break it.
5.11 Operational 5.11 Operational
5.11.1 Ability to assign transport quality to signaling messages 5.11.1 Ability to assign transport quality to signaling messages.
The NSIS architecture should allow the network operator to assign The NSIS architecture should allow the network operator to assign
the NSIS protocol messages a certain transport quality. As signaling the NSIS protocol messages a certain transport quality. As signaling
opens up for possible denial-of-service attacks, this requirement opens up for possible denial-of-service attacks, this requirement
gives the network operator a mean, but also the obligation, to gives the network operator a mean, but also the obligation, to
trade-off between signaling latency and the impact (from the trade-off between signaling latency and the impact (from the
signaling messages) on devices within his/her network. From protocol signaling messages) on devices within his/her network. From protocol
design this requirement states that the protocol messages should be design this requirement states that the protocol messages should be
detectable, at least where the control and assignment of the detectable, at least where the control and assignment of the
messages priority is done. messages priority is done.
Furthermore, the protocol design must take into account reliability
concerns.
Communication reliability is seen as part of the quality assigned to
signaling messages. So procedures must define how an NSIS signaling
systems behaves if some kind of request it sent stays without
answer. The basic transport protocol to be used between adjacent
NSIS units must ensure message integrity and reliable transport.
5.11.2 Graceful fail over
Any unit participating in NSIS signaling must not cause further
damage to other systems involved in NSIS signaling when it has to go
out of service.
6 The MUSTs, SHOULDs, and MAYs 6 The MUSTs, SHOULDs, and MAYs
Requirements for QoS Signaling Protocols July 2002
In order to prioritize the various requirements from Section 5, we In order to prioritize the various requirements from Section 5, we
define different 'parts of the network'. In the different parts of define different 'parts of the network'. In the different parts of
the network a particular requirement might have a different the network a particular requirement might have a different
priority. priority.
The parts of the networks we differentiate are the host-to-first The parts of the networks we differentiate are the host-to-first
router, the access network, and the core network. The host to first router, the access network, and the core network. The host to first
router part includes all the layer 2 technologies to access to the router part includes all the layer 2 technologies to access to the
Internet. In many cases, there is an application and/or user running Internet. In many cases, there is an application and/or user running
on the host initiating QoS signaling. The access network can be on the host initiating QoS signaling. The access network can be
characterized by low capacity links, meadium speed IP processing characterized by low capacity links, medium speed IP processing
capabilities, and it might consist of a complete layer 2 network as capabilities, and it might consist of a complete layer 2 networks as
well. The core network characteristics include high-speed forwarding well. The core network characteristics include high-speed forwarding
capacities and interdomain QoS issues. All of them are not strictly capacities and interdomain QoS issues. All of them are not strictly
defined and should not be regarded as that, but should give a defined and should not be regarded as that, but should give a
feeling about where in the network we have different requirements feeling about where in the network we have different requirements
concerning QoS signaling. concerning QoS signaling.
Note that the requirement titles are listed for better reading. Note that the requirement titles are listed for better reading.
5.1 Architecture and Design Goals 5.1 Architecture and Design Goals
5.1.1 Applicability for different QoS technologies. 5.1.1 Applicability for different QoS technologies.
skipping to change at line 1155 skipping to change at page 25, line 42
5.1.6 Independence of signaling and provisioning paradigm 5.1.6 Independence of signaling and provisioning paradigm
----------------------+-------------+-------------+------------+ ----------------------+-------------+-------------+------------+
| host-to-net | access | core | | host-to-net | access | core |
----------------------+-------------+-------------+------------+ ----------------------+-------------+-------------+------------+
5.1.1 | | | | 5.1.1 | | | |
----------------------+-------------+-------------+------------+ ----------------------+-------------+-------------+------------+
5.1.2 | | | | 5.1.2 | | | |
----------------------+-------------+-------------+------------+ ----------------------+-------------+-------------+------------+
5.1.3 | | | | 5.1.3 | | | |
Brunner, et al. Informational [Page 21]
Requirements for QoS Signaling Protocols May 2002
----------------------+-------------+-------------+------------+ ----------------------+-------------+-------------+------------+
5.1.4 | | | | 5.1.4 | | | |
----------------------+-------------+-------------+------------+ ----------------------+-------------+-------------+------------+
5.1.5 | | | | 5.1.5 | | | |
----------------------+-------------+-------------+------------+ ----------------------+-------------+-------------+------------+
5.1.6 | | | | 5.1.6 | | | |
----------------------+-------------+-------------+------------+ ----------------------+-------------+-------------+------------+
5.2 Signaling Flows 5.2 Signaling Flows
5.2.1 Free placement of QoS Initiator and QoS Controllers functions 5.2.1 Free placement of QoS Initiator and QoS Controllers functions
5.2.2 No constraint of the QoS signaling and QoS Controllers to be 5.2.2 No constraint of the QoS signaling and QoS Controllers to be
in the data path. in the data path.
5.2.3 Concealment of topology and technology information 5.2.3 Concealment of topology and technology information
5.2.4 Optional transparency of QoS signaling to network 5.2.4 Optional transparency of QoS signaling to network
----------------------+-------------+-------------+------------+ ----------------------+-------------+-------------+------------+
Requirements for QoS Signaling Protocols July 2002
| host-to-net | access | core | | host-to-net | access | core |
----------------------+-------------+-------------+------------+ ----------------------+-------------+-------------+------------+
5.2.1 | | | | 5.2.1 | | | |
----------------------+-------------+-------------+------------+ ----------------------+-------------+-------------+------------+
5.2.2 | | | | 5.2.2 | | | |
----------------------+-------------+-------------+------------+ ----------------------+-------------+-------------+------------+
5.2.3 | | | | 5.2.3 | | | |
----------------------+-------------+-------------+------------+ ----------------------+-------------+-------------+------------+
5.2.4 | | | | 5.2.4 | | | |
----------------------+-------------+-------------+------------+ ----------------------+-------------+-------------+------------+
skipping to change at line 1213 skipping to change at page 26, line 43
----------------------+-------------+-------------+------------+ ----------------------+-------------+-------------+------------+
5.3.3 | | | | 5.3.3 | | | |
----------------------+-------------+-------------+------------+ ----------------------+-------------+-------------+------------+
5.3.4 | | | | 5.3.4 | | | |
----------------------+-------------+-------------+------------+ ----------------------+-------------+-------------+------------+
5.3.5 | | | | 5.3.5 | | | |
----------------------+-------------+-------------+------------+ ----------------------+-------------+-------------+------------+
5.3.6 | | | | 5.3.6 | | | |
----------------------+-------------+-------------+------------+ ----------------------+-------------+-------------+------------+
Brunner, et al. Informational [Page 22]
Requirements for QoS Signaling Protocols May 2002
5.4 Layering 5.4 Layering
5.4.1 The signaling protocol and QoS control information should be 5.4.1 The signaling protocol and QoS control information should be
application independent. application independent.
----------------------+-------------+-------------+------------+ ----------------------+-------------+-------------+------------+
| host-to-net | access | core | | host-to-net | access | core |
----------------------+-------------+-------------+------------+ ----------------------+-------------+-------------+------------+
5.4.1 | | | | 5.4.1 | | | |
----------------------+-------------+-------------+------------+ ----------------------+-------------+-------------+------------+
5.5 QoS Control Information 5.5 QoS Control Information
5.5.1 Mutability information on parameters 5.5.1 Mutability information on parameters
5.5.2 Possibility to add and remove local domain information 5.5.2 Possibility to add and remove local domain information
5.5.3 Independence of reservation identifier 5.5.3 Independence of reservation identifier
5.5.4 Seamless modification of already reserved QoS 5.5.4 Seamless modification of already reserved QoS
Requirements for QoS Signaling Protocols July 2002
5.5.5 Signaling must support quantitative, qualitative, and relative 5.5.5 Signaling must support quantitative, qualitative, and relative
QoS specifications QoS specifications
----------------------+-------------+-------------+------------+ ----------------------+-------------+-------------+------------+
| host-to-net | access | core | | host-to-net | access | core |
----------------------+-------------+-------------+------------+ ----------------------+-------------+-------------+------------+
5.5.1 | | | | 5.5.1 | | | |
----------------------+-------------+-------------+------------+ ----------------------+-------------+-------------+------------+
5.5.2 | | | | 5.5.2 | | | |
----------------------+-------------+-------------+------------+ ----------------------+-------------+-------------+------------+
skipping to change at line 1269 skipping to change at page 27, line 42
5.6.5 Scalability in CPU use (end terminal and intermediate nodes) 5.6.5 Scalability in CPU use (end terminal and intermediate nodes)
5.6.6 Low latency in setup 5.6.6 Low latency in setup
5.6.7 Allow for low bandwidth consumption for signaling protocol 5.6.7 Allow for low bandwidth consumption for signaling protocol
5.6.8 Ability to constrain load on devices 5.6.8 Ability to constrain load on devices
5.6.9 Highest possible network utilization 5.6.9 Highest possible network utilization
----------------------+-------------+-------------+------------+ ----------------------+-------------+-------------+------------+
| host-to-net | access | core | | host-to-net | access | core |
----------------------+-------------+-------------+------------+ ----------------------+-------------+-------------+------------+
5.6.1 | | | | 5.6.1 | | | |
Brunner, et al. Informational [Page 23]
Requirements for QoS Signaling Protocols May 2002
----------------------+-------------+-------------+------------+ ----------------------+-------------+-------------+------------+
5.6.2 | | | | 5.6.2 | | | |
----------------------+-------------+-------------+------------+ ----------------------+-------------+-------------+------------+
5.6.3 | | | | 5.6.3 | | | |
----------------------+-------------+-------------+------------+ ----------------------+-------------+-------------+------------+
5.6.4 | | | | 5.6.4 | | | |
----------------------+-------------+-------------+------------+ ----------------------+-------------+-------------+------------+
5.6.5 | | | | 5.6.5 | | | |
----------------------+-------------+-------------+------------+ ----------------------+-------------+-------------+------------+
5.6.6 | | | | 5.6.6 | | | |
----------------------+-------------+-------------+------------+ ----------------------+-------------+-------------+------------+
5.6.7 | | | | 5.6.7 | | | |
----------------------+-------------+-------------+------------+ ----------------------+-------------+-------------+------------+
5.6.8 | | | | 5.6.8 | | | |
----------------------+-------------+-------------+------------+ ----------------------+-------------+-------------+------------+
5.6.9 | | | | 5.6.9 | | | |
----------------------+-------------+-------------+------------+ ----------------------+-------------+-------------+------------+
Requirements for QoS Signaling Protocols July 2002
5.7 Flexibility 5.7 Flexibility
5.7.1 Aggregation capability, including the capability to select and 5.7.1 Aggregation capability, including the capability to select and
change the level of aggregation. change the level of aggregation.
5.7.2 Flexibility in the placement of the QoS initiator 5.7.2 Flexibility in the placement of the QoS initiator
5.7.3 Flexibility in the initiation of re-negotiation (QoS change 5.7.3 Flexibility in the initiation of re-negotiation (QoS change
requests) requests)
5.7.4 Uni / bi-directional reservation 5.7.4 Uni / bi-directional reservation
skipping to change at line 1326 skipping to change at page 28, line 41
requests requests
5.8.3 The QoS signaling messages must provide integrity protection. 5.8.3 The QoS signaling messages must provide integrity protection.
5.8.4 The QoS signaling messages must be replay protected. 5.8.4 The QoS signaling messages must be replay protected.
5.8.5 The QoS signaling protocol must allow for hop-by-hop security. 5.8.5 The QoS signaling protocol must allow for hop-by-hop security.
5.8.6 The QoS protocol should allow identity confidentiality and 5.8.6 The QoS protocol should allow identity confidentiality and
location privacy. location privacy.
5.8.7 The QoS protocol should prevent denial-of-service attacks 5.8.7 The QoS protocol should prevent denial-of-service attacks
against signaling entities. against signaling entities.
5.8.8 The QoS protocol should support confidentiality of signaling 5.8.8 The QoS protocol should support confidentiality of signaling
messages. messages.
Brunner, et al. Informational [Page 24]
Requirements for QoS Signaling Protocols May 2002
5.8.9 The QoS protocol should provide hooks to interact with 5.8.9 The QoS protocol should provide hooks to interact with
protocols that allow the negotiation of authentication and key protocols that allow the negotiation of authentication and key
management protocols. management protocols.
5.8.10 The QoS protocol should provide means to interact with key 5.8.10 The QoS protocol should provide means to interact with key
management protocols. management protocols.
----------------------+-------------+-------------+------------+ ----------------------+-------------+-------------+------------+
| host-to-net | access | core | | host-to-net | access | core |
----------------------+-------------+-------------+------------+ ----------------------+-------------+-------------+------------+
5.8.1 | | | | 5.8.1 | | | |
----------------------+-------------+-------------+------------+ ----------------------+-------------+-------------+------------+
5.8.2 | | | | 5.8.2 | | | |
----------------------+-------------+-------------+------------+ ----------------------+-------------+-------------+------------+
5.8.3 | | | | 5.8.3 | | | |
----------------------+-------------+-------------+------------+ ----------------------+-------------+-------------+------------+
5.8.4 | | | | 5.8.4 | | | |
----------------------+-------------+-------------+------------+ ----------------------+-------------+-------------+------------+
5.8.5 | | | | 5.8.5 | | | |
----------------------+-------------+-------------+------------+ ----------------------+-------------+-------------+------------+
Requirements for QoS Signaling Protocols July 2002
5.8.6 | | | | 5.8.6 | | | |
----------------------+-------------+-------------+------------+ ----------------------+-------------+-------------+------------+
5.8.7 | | | | 5.8.7 | | | |
----------------------+-------------+-------------+------------+ ----------------------+-------------+-------------+------------+
5.8.8 | | | | 5.8.8 | | | |
----------------------+-------------+-------------+------------+ ----------------------+-------------+-------------+------------+
5.8.9 | | | | 5.8.9 | | | |
----------------------+-------------+-------------+------------+ ----------------------+-------------+-------------+------------+
5.8.10 | | | | 5.8.10 | | | |
----------------------+-------------+-------------+------------+ ----------------------+-------------+-------------+------------+
skipping to change at line 1376 skipping to change at page 29, line 33
5.9.1 | | | | 5.9.1 | | | |
----------------------+-------------+-------------+------------+ ----------------------+-------------+-------------+------------+
5.10 Interworking with other protocols and techniques 5.10 Interworking with other protocols and techniques
5.10.1 Interworking with IP tunneling 5.10.1 Interworking with IP tunneling
5.10.2 The solution should not constrain either to IPv4 or IPv6 5.10.2 The solution should not constrain either to IPv4 or IPv6
5.10.3 Independence from charging model 5.10.3 Independence from charging model
5.10.4 The QoS protocol should provide hooks for AAA protocols 5.10.4 The QoS protocol should provide hooks for AAA protocols
5.10.5 Interworking with seamless handoff protocols
5.10.6 Interworking with non-traditional routing
----------------------+-------------+-------------+------------+ ----------------------+-------------+-------------+------------+
| host-to-net | access | core | | host-to-net | access | core |
----------------------+-------------+-------------+------------+ ----------------------+-------------+-------------+------------+
5.10.1 | | | | 5.10.1 | | | |
----------------------+-------------+-------------+------------+ ----------------------+-------------+-------------+------------+
5.10.2 | | | | 5.10.2 | | | |
Brunner, et al. Informational [Page 25]
Requirements for QoS Signaling Protocols May 2002
----------------------+-------------+-------------+------------+ ----------------------+-------------+-------------+------------+
5.10.3 | | | | 5.10.3 | | | |
----------------------+-------------+-------------+------------+ ----------------------+-------------+-------------+------------+
5.10.4 | | | | 5.10.4 | | | |
----------------------+-------------+-------------+------------+ ----------------------+-------------+-------------+------------+
5.10.5 | | | |
----------------------+-------------+-------------+------------+
5.10.6 | | | |
----------------------+-------------+-------------+------------+
5.11 Operational 5.11 Operational
5.11.1 Ability to assign transport quality to signaling messages 5.11.1 Ability to assign transport quality to signaling messages
----------------------+-------------+-------------+------------+ ----------------------+-------------+-------------+------------+
| host-to-net | access | core | | host-to-net | access | core |
----------------------+-------------+-------------+------------+ ----------------------+-------------+-------------+------------+
Requirements for QoS Signaling Protocols July 2002
5.11.1 | | | | 5.11.1 | | | |
----------------------+-------------+-------------+------------+ ----------------------+-------------+-------------+------------+
7 References 7 References
[1] Kempf, J., "Dormant Mode Host Alerting ("IP Paging") Problem [1] Kempf, J., "Dormant Mode Host Alerting ("IP Paging") Problem
Statement", RFC 3132, June 2001. Statement", RFC 3132, June 2001.
[2] Chaskar, H., "Requirements of a QoS Solution for Mobile IP", [2] Chaskar, H., "Requirements of a QoS Solution for Mobile IP",
draft-ietf-mobileip-qos-requirements-01.txt, Work in Progress, draft-ietf-mobileip-qos-requirements-01.txt, Work in Progress,
skipping to change at line 1439 skipping to change at page 30, line 46
[9] Braden, R., Zhang, L., Berson, S., Herzog, A., Jamin, S., [9] Braden, R., Zhang, L., Berson, S., Herzog, A., Jamin, S.,
"Resource ReSerVation Protocol (RSVP) -- Version 1 Functional "Resource ReSerVation Protocol (RSVP) -- Version 1 Functional
Specification", IETF RFC 2205, 1997. Specification", IETF RFC 2205, 1997.
[10] Westberg, L., Jacobsson, M., Partain, D., Karagiannis, G., [10] Westberg, L., Jacobsson, M., Partain, D., Karagiannis, G.,
Oosthoek, S., Rexhepi, V., Szabo, R., Wallentin, P., "Resource Oosthoek, S., Rexhepi, V., Szabo, R., Wallentin, P., "Resource
Management in Diffserv Framework", Internet draft, work in progress, Management in Diffserv Framework", Internet draft, work in progress,
draft-westberg-rmd-framework-xx.txt, 2002. draft-westberg-rmd-framework-xx.txt, 2002.
Brunner, et al. Informational [Page 26]
Requirements for QoS Signaling Protocols May 2002
[11] Kempf, J., McCann, P., Roberts, P., "IP Mobility and the CDMA [11] Kempf, J., McCann, P., Roberts, P., "IP Mobility and the CDMA
Radio Access Network", IETF Draft, draft-kempf-cdma-appl-02.txt, Radio Access Network", IETF Draft, draft-kempf-cdma-appl-02.txt,
Work in progress, September 2001. Work in progress, September 2001.
8 Appendix: Scenarios/Use cases [12] Tschofenig, H., "NSIS Threats", <draft-tschofenig-nsis-threats-
00.txt>, May 2002.
8 Acknowledgments
Quite a number of people have been involved in the discussion of the
draft, adding some ideas, requirements, etc. We list them without a
guarantee on completeness: Changpeng Fan (Siemens), Krishna Paul
(NEC), Maurizio Molina (NEC), Mirko Schramm (Siemens), Andreas
Requirements for QoS Signaling Protocols July 2002
Schrader (NEC), Hannes Hartenstein (NEC), Ralf Schmitz (NEC),
Juergen Quittek (NEC), Morihisa Momona (NEC), Holger Karl (Technical
University Berlin), Xiaoming Fu (Technical University Berlin), Hans-
Peter Schwefel (Siemens), Mathias Rautenberg (Siemens), Christoph
Niedermeier (Siemens), Andreas Kassler (University of Ulm), Ilya
Freytsis.
Some text and/or ideas for text, requirements, scenarios have been
taken from a draft written by the following authors: David Partain
(Ericsson), Anders Bergsten (Telia Research), Marc Greis (Nokia),
Georgios Karagiannis (Ericsson), Jukka Manner (University of
Helsinki), Ping Pan (Juniper), Vlora Rexhepi (Ericsson), Lars
Westberg (Ericsson), Haihong Zheng (Nokia). Some of those have
actively contributed new text to the draft as well.
Another draft impacting this draft has been written by Sven Van den
Bosch, Maarten Buchli, and Danny Goderis. These people contributed
also with new text.
9 Author's Addresses
Marcus Brunner (Editor)
NEC Europe Ltd.
Network Laboratories
Adenauerplatz 6
D-69115 Heidelberg
Germany
E-Mail: brunner@ccrle.nec.de (contact)
Robert Hancock, Eleanor Hepworth
Roke Manor Research Ltd
Romsey, Hants, SO51 0ZN
United Kingdom
E-Mail: [robert.hancock|eleanor.hepworth]@roke.co.uk
Cornelia Kappler
Siemens AG
Berlin 13623
Germany
E-Mail: cornelia.kappler@icn.siemens.de
Hannes Tschofenig
Siemens AG
Otto-Hahn-Ring 6
81739 Munchen
Germany
Email: Hannes.Tschofenig@mchp.siemens.de
10 Appendix: Scenarios/Use cases
In the following we describe scenarios, which are important to In the following we describe scenarios, which are important to
cover, and which allow us to discuss various requirements. Some cover, and which allow us to discuss various requirements. Some
Requirements for QoS Signaling Protocols July 2002
regard this as use cases to be covered defining the use of a QoS regard this as use cases to be covered defining the use of a QoS
signaling protocol. signaling protocol.
8.1 Scenario: Terminal Mobility 10.1 Scenario: Terminal Mobility
The scenario we are looking at is the case where a mobile terminal The scenario we are looking at is the case where a mobile terminal
(MT) changes from one access point to another access point. The (MT) changes from one access point to another access point. The
access points are located in separate QoS domains. We assume Mobile access points are located in separate QoS domains. We assume Mobile
IP to handle mobility on the network layer in this scenario and IP to handle mobility on the network layer in this scenario and
consider the various extensions (i.e., IETF proposals) to Mobile IP, consider the various extensions (i.e., IETF proposals) to Mobile IP,
in order to provide 'fast handover' for roaming Mobile Terminals. in order to provide 'fast handover' for roaming Mobile Terminals.
The goal to be achieved lies in providing, keeping, and adapting the The goal to be achieved lies in providing, keeping, and adapting the
requested QoS for the ongoing IP sessions in case of handover. requested QoS for the ongoing IP sessions in case of handover.
Furthermore, the negotiation of QoS parameters with the new domain Furthermore, the negotiation of QoS parameters with the new domain
skipping to change at line 1494 skipping to change at page 32, line 50
- The QoS management requests handoff. The QoS management can decide - The QoS management requests handoff. The QoS management can decide
to change the access point, since the traffic conditions of the new to change the access point, since the traffic conditions of the new
access point are better supporting the QoS requirements. The metric access point are better supporting the QoS requirements. The metric
may be different (optimized towards a single or a group/class of may be different (optimized towards a single or a group/class of
users). Note that the MT or the network (see below) might trigger users). Note that the MT or the network (see below) might trigger
the handoff. the handoff.
- The mobility management forces handoff. This can have several - The mobility management forces handoff. This can have several
reasons. The operator optimizes his network, admission is no longer reasons. The operator optimizes his network, admission is no longer
Brunner, et al. Informational [Page 27]
Requirements for QoS Signaling Protocols May 2002
granted (e.g. emptied prepaid condition). Or another example is when granted (e.g. emptied prepaid condition). Or another example is when
the MT is reaching the focus of another base station. However, this the MT is reaching the focus of another base station. However, this
might be detected via measurements of QoS on the physical layer and might be detected via measurements of QoS on the physical layer and
is therefore out of scope of QoS signaling in IP. Note again that is therefore out of scope of QoS signaling in IP. Note again that
the MT or the network (see below) might trigger the handoff. the MT or the network (see below) might trigger the handoff.
- This scenario shows that local decisions might not be enough. The - This scenario shows that local decisions might not be enough. The
rest of the path to the other end of the communication needs to be rest of the path to the other end of the communication needs to be
considered as well. Hand-off decisions in a QoS domain, does not considered as well. Hand-off decisions in a QoS domain, does not
only depend on the local resource availability, e.g., the wireless only depend on the local resource availability, e.g., the wireless
Requirements for QoS Signaling Protocols July 2002
part, but involves the rest of the path as well. Additionally, part, but involves the rest of the path as well. Additionally,
decomposition of an end-to-end reservation might be needed, in order decomposition of an end-to-end reservation might be needed, in order
to change only parts of it. to change only parts of it.
2) Trigger sources 2) Trigger sources
- Mobile terminal: If the end-system QoS management identifies - Mobile terminal: If the end-system QoS management identifies
another (better-suited) access point, it will request the handoff another (better-suited) access point, it will request the handoff
from the terminal itself. This will be especially likely in the case from the terminal itself. This will be especially likely in the case
that two different provider networks are involved. Another important that two different provider networks are involved. Another important
skipping to change at line 1552 skipping to change at page 33, line 50
(macro-diversity), the handover rate is significantly higher (see (macro-diversity), the handover rate is significantly higher (see
for example [11]) for example [11])
5) Fast reservations 5) Fast reservations
Handover can also cause packet losses. This happens when the Handover can also cause packet losses. This happens when the
processing of an admission request causes a delayed handover to the processing of an admission request causes a delayed handover to the
new base station. In this situation, some packets might be new base station. In this situation, some packets might be
discarded, and the overall speech quality might be degraded discarded, and the overall speech quality might be degraded
significantly. Moreover, a delay in handover may cause degradation significantly. Moreover, a delay in handover may cause degradation
for other users. In the worst-case scenario, a delay in handover may
Brunner, et al. Informational [Page 28]
Requirements for QoS Signaling Protocols May 2002
for other users. In the worst case scenario, a delay in handover may
cause the connection to be dropped if the handover occurred due to cause the connection to be dropped if the handover occurred due to
bad air link quality. Therefore, it is critical that QoS signalling bad air link quality. Therefore, it is critical that QoS signaling
in connection with handover be carried out very quickly. in connection with handover be carried out very quickly.
6) Call blocking in case of overload 6) Call blocking in case of overload
Furthermore, when the network is overloaded, it is preferable to Furthermore, when the network is overloaded, it is preferable to
keep reservations for previously established flows while blocking keep reservations for previously established flows while blocking
new requests. Therefore, the resource reservation requests in new requests. Therefore, the resource reservation requests in
Requirements for QoS Signaling Protocols July 2002
connection with handover should be given higher priority than new connection with handover should be given higher priority than new
requests for resource reservation. requests for resource reservation.
8.2 Scenario: Cellular Networks 10.2 Scenario: Cellular Networks
In this scenario, the user is using the packet service of a 3rd In this scenario, the user is using the packet service of a 3rd
generation cellular system, e.g. UMTS. The region between the End generation cellular system, e.g. UMTS. The region between the End
Host and the edge node connecting the cellular network to another Host and the edge node connecting the cellular network to another
QoS domain (e.g. the GGSN in UMTS or the PDSN in 3GPP2) is QoS domain (e.g. the GGSN in UMTS or the PDSN in 3GPP2) is
considered to be a single QoS domain [4][5]. considered to be a single QoS domain [4][5].
The issues in such an environment regarding QoS include: The issues in such an environment regarding QoS include:
1) Cellular systems provide their own QoS technology with 1) Cellular systems provide their own QoS technology with
specialized parameters to co-ordinate the QoS provided by both the specialized parameters to co-ordinate the QoS provided by both the
radio access and wired access network. For example, in a UMTS radio access and wired access network. For example, in a UMTS
network, one aspect of GPRS is that it can be considered as a QoS network, one aspect of GPRS is that it can be considered as a QoS
technology; provisioning of QoS within GPRS is described mainly in technology; provisioning of QoS within GPRS is described mainly in
terms of calling UMTS bearer classes. This QoS technology needs to terms of calling UMTS bearer classes. This QoS technology needs to
be invoked with suitable parameters when a request for QoS is be invoked with suitable parameters when higher layers trigger a
triggered by higher layers, and this therefore involves mapping the request for QoS, and this therefore involves mapping the requested
requested IP QoS onto these UMTS bearer classes. This request for IP QoS onto these UMTS bearer classes. This request for resources
resources might be triggered by IP signaling messages that pass might be triggered by IP signaling messages that pass across the
across the cellular system, and possibly other QoS domains, to cellular system, and possibly other QoS domains, to negotiate for
negotiate for network resources. Typically, cellular system specific network resources. Typically, cellular system specific messages
messages invoke the underlying cellular system QoS technology in invoke the underlying cellular system QoS technology in parallel
parallel with the IP QoS negotiation, to allocate the resources with the IP QoS negotiation, to allocate the resources within the
within the cellular system. cellular system.
2) The placement of QoS initiators and QoS controllers (terminology 2) The placement of QoS initiators and QoS controllers (terminology
in the framework given here). The QoS initiator could be located at in the framework given here). The QoS initiator could be located at
the End Host (triggered by applications), the GGSN/PDSN, or at a the End Host (triggered by applications), the GGSN/PDSN, or at a
node not directly on the data path, such as a bandwidth broker. In node not directly on the data path, such as a bandwidth broker. In
the second case, the GGSN/PDSN could either be acting as a proxy on the second case, the GGSN/PDSN could either be acting as a proxy on
behalf of an End Host with little capabilities, and/or managing behalf of an End Host with little capabilities, and/or managing
aggregate resources within its QoS domain (the UMTS core network). aggregate resources within its QoS domain (the UMTS core network).
The IP signaling messages are interpreted by the QoS controllers, The IP signaling messages are interpreted by the QoS controllers,
which may be located at the GGSN/PDSN, and in any QoS sub-domains which may be located at the GGSN/PDSN, and in any QoS sub-domains
within the cellular system. within the cellular system.
3) Initiation of IP-level QoS negotiation. IP-level QoS re- 3) Initiation of IP-level QoS negotiation. IP-level QoS re-
negotiation may be initiated by either the End Host, or by the negotiation may be initiated by either the End Host, or by the
network, based on current network loads, which might change network, based on current network loads, which might change
depending on the location of the end host. depending on the location of the end host.
Brunner, et al. Informational [Page 29]
Requirements for QoS Signaling Protocols May 2002
4) The networks are designed and mainly used for speech 4) The networks are designed and mainly used for speech
communication (at least so far). communication (at least so far).
Note that in comparison to the former scenario, the emphasis is much Note that in comparison to the former scenario, the emphasis is much
less on the mobility aspects, because mobility is mainly handled on less on the mobility aspects, because mobility is mainly handled on
the lower layer. the lower layer.
8.3 Scenario: UMTS access 10.3 Scenario: UMTS access
Requirements for QoS Signaling Protocols July 2002
The UMTS access scenario is shown in figure 3. The Proxy-Call State The UMTS access scenario is shown in figure 3. The Proxy-Call State
Control Function/Policy Control Function (P-CSCF/PCF) is the Control Function/Policy Control Function (P-CSCF/PCF) is the
outbound SIP proxy of the visited domain, i.e. the domain where the outbound SIP proxy of the visited domain, i.e. the domain where the
mobile user wants to set-up a call. The Gateway GPRS Support Node mobile user wants to set-up a call. The Gateway GPRS Support Node
(GGSN) is the egress router of the UMTS domain and connects the UMTS (GGSN) is the egress router of the UMTS domain and connects the UMTS
access network to the Edge Router (ER) of the core IP network. The access network to the Edge Router (ER) of the core IP network. The
P-CSCF/PCF communicates with the GGSN via the COPS protocol [4]. The P-CSCF/PCF communicates with the GGSN via the COPS protocol [4]. The
User Equipment (UE) consists of a Mobile Terminal (MT) and Terminal User Equipment (UE) consists of a Mobile Terminal (MT) and Terminal
Equipment (TE), e.g. a laptop. Equipment (TE), e.g. a laptop.
skipping to change at line 1665 skipping to change at page 35, line 48
has all required QoS information for per-flow admission control in has all required QoS information for per-flow admission control in
the UMTS access network (which it gets from the P-CSCF and/or GGSN). the UMTS access network (which it gets from the P-CSCF and/or GGSN).
Thus the PCF would be the appropriate entity to host the Thus the PCF would be the appropriate entity to host the
functionality of QI, initiating the "NSIS" QoS signaling towards the functionality of QI, initiating the "NSIS" QoS signaling towards the
core IP network. The PCF/P-CSCF has to do the mapping from codec core IP network. The PCF/P-CSCF has to do the mapping from codec
type (derived from SIP/SDP signaling) to IP traffic descriptor. SDP type (derived from SIP/SDP signaling) to IP traffic descriptor. SDP
extensions to explicitly signal QoS information [7] are useful to extensions to explicitly signal QoS information [7] are useful to
avoid the need to store codec information in the PCF and to allow avoid the need to store codec information in the PCF and to allow
for more flexibility and accurate description of the QoS traffic for more flexibility and accurate description of the QoS traffic
parameters. The PCF also controls the GGSN to open and close the parameters. The PCF also controls the GGSN to open and close the
Brunner, et al. Informational [Page 30]
Requirements for QoS Signaling Protocols May 2002
gates and to configure per-flow policers, i.e. to authorize or gates and to configure per-flow policers, i.e. to authorize or
forbid user traffic. forbid user traffic.
The QC is (of course) not part of the standard UMTS architecture. The QC is (of course) not part of the standard UMTS architecture.
However, to achieve end-to-end QoS a QC is needed such that the PCF However, to achieve end-to-end QoS a QC is needed such that the PCF
can request a QoS connection to the IP network. As in the previous can request a QoS connection to the IP network. As in the previous
example, the QC could manage a set of pre-provisioned resources in example, the QC could manage a set of pre-provisioned resources in
the IP network, i.e. bandwidth pipes, and the QC performs per-flow the IP network, i.e. bandwidth pipes, and the QC performs per-flow
admission control into these pipes. In this way, a connection can be admission control into these pipes. In this way, a connection can be
made between two UMTS access networks, and hence, end-to-end QoS can made between two UMTS access networks, and hence, end-to-end QoS can
Requirements for QoS Signaling Protocols July 2002
be achieved. In this case the QI and QC are clearly two separate be achieved. In this case the QI and QC are clearly two separate
entities. entities.
This use case clearly illustrates the need for an "NSIS" QoS This use case clearly illustrates the need for an "NSIS" QoS
signaling protocol between QI and QC. An important application of signaling protocol between QI and QC. An important application of
such a protocol may be its use in the inter-connection of UMTS such a protocol may be its use in the inter-connection of UMTS
networks over an IP backbone. networks over an IP backbone.
8.4 Wired part of wireless network 10.4 Scenario: Wired part of wireless network
A wireless network, seen from a QoS domain perspective, usually A wireless network, seen from a QoS domain perspective, usually
consists of three parts: a wireless interface part (the "radio consists of three parts: a wireless interface part (the "radio
interface"), a wired part of the wireless network (i.e., Radio interface"), a wired part of the wireless network (i.e., Radio
Access Network) and the backbone of the wireless network, as shown Access Network) and the backbone of the wireless network, as shown
in Figure 2. Note that this figure should not be seen as an in Figure 2. Note that this figure should not be seen as an
architectural overview of wireless networks but rather as showing architectural overview of wireless networks but rather as showing
the conceptual QoS domains in a wireless network. the conceptual QoS domains in a wireless network.
In this scenario, a mobile host can roam and perform a handover In this scenario, a mobile host can roam and perform a handover
skipping to change at line 1723 skipping to change at page 36, line 50
...|ER|.......|ER|..|BGW|.."Internet"..|host| ...|ER|.......|ER|..|BGW|.."Internet"..|host|
-- |-------| |--| . |--| bone |--| |---| -- |-------| |--| . |--| bone |--| |---|
|----| |----|
|--| \ |base |-|ER|... . |--| \ |base |-|ER|... .
|MH| \ |station| |--| . |MH| \ |station| |--| .
|--|--- |-------| . MH = mobile host |--|--- |-------| . MH = mobile host
|--| ER = edge router |--| ER = edge router
<----> |GW| GW = gateway <----> |GW| GW = gateway
Wireless link |--| BGW = border gateway Wireless link |--| BGW = border gateway
Brunner, et al. Informational [Page 31]
Requirements for QoS Signaling Protocols May 2002
... = interior nodes ... = interior nodes
<-------------------> <------------------->
Wired part of wireless network Wired part of wireless network
<----------------------------------------> <---------------------------------------->
Wireless Network Wireless Network
Figure 2. QoS architecture of wired part of wireless network Figure 2. QoS architecture of wired part of wireless network
Requirements for QoS Signaling Protocols July 2002
Each of these parts of the wireless network impose different issues Each of these parts of the wireless network impose different issues
to be solved on the QoS signaling solution being used: to be solved on the QoS signaling solution being used:
* Wireless interface: The solution for the air interface link * Wireless interface: The solution for the air interface link
has to ensure flexibility and spectrum efficient transmission has to ensure flexibility and spectrum efficient transmission
of IP packets. However, this link layer QoS can be solved in of IP packets. However, this link layer QoS can be solved in
the same way as any other last hop problem by allowing a the same way as any other last hop problem by allowing a
host to request the proper QoS profile. host to request the proper QoS profile.
skipping to change at line 1781 skipping to change at page 37, line 51
4. The wired transmission in such a network contains a 4. The wired transmission in such a network contains a
relatively high volume of expensive leased lines. relatively high volume of expensive leased lines.
Overprovisioning might therefore be prohibitively Overprovisioning might therefore be prohibitively
expensive. expensive.
5. The radio base stations are spread over a wide 5. The radio base stations are spread over a wide
geographical area and are in general situated a large geographical area and are in general situated a large
distance from the backbone. distance from the backbone.
Brunner, et al. Informational [Page 32]
Requirements for QoS Signaling Protocols May 2002
* Backbone of the wireless network: the requirements imposed * Backbone of the wireless network: the requirements imposed
by this network are similar to the requirements imposed by by this network are similar to the requirements imposed by
other types of backbone networks. other types of backbone networks.
Due to these very different characteristics and requirements, often Due to these very different characteristics and requirements, often
contradictory, different QoS signalling solutions might be needed in contradictory, different QoS signaling solutions might be needed in
each of the three network parts. each of the three network parts.
8.5 Scenario: Session Mobility Requirements for QoS Signaling Protocols July 2002
10.5 Scenario: Session Mobility
In this scenario, a session is moved from one end-system to another. In this scenario, a session is moved from one end-system to another.
Ongoing sessions are kept and QoS parameters need to be adapted, Ongoing sessions are kept and QoS parameters need to be adapted,
since it is very likely that the new device provides different since it is very likely that the new device provides different
capabilities. Note that it is open which entity initiates the move, capabilities. Note that it is open which entity initiates the move,
which implies that the QoS initiator might be triggered by different which implies that the QoS initiator might be triggered by different
entities. entities.
User mobility (i.e., a user changing the device and therefore moving User mobility (i.e., a user changing the device and therefore moving
the sessions to the new device) is considered to be a special case the sessions to the new device) is considered to be a special case
skipping to change at line 1819 skipping to change at page 38, line 34
The issues include: The issues include:
1) Keeping the QoS guarantees negotiated implies that the end- 1) Keeping the QoS guarantees negotiated implies that the end-
point(s) of communication are changed without changing the point(s) of communication are changed without changing the
reservations. reservations.
2) The trigger of the session move might be the user or any other 2) The trigger of the session move might be the user or any other
party involved in the session. party involved in the session.
8.6 Scenario: QoS reservations/negotiation from access to core network 10.6 Scenario: QoS reservations/negotiation from access to core
network
The scenario includes the signaling between access networks and core The scenario includes the signaling between access networks and core
networks in order to setup and change reservations together with networks in order to setup and change reservations together with
potential negotiation. potential negotiation.
The issues to be solved in this scenario are different from previous The issues to be solved in this scenario are different from previous
ones. ones.
1) The entity of reservation is most likely an aggregate. 1) The entity of reservation is most likely an aggregate.
2) The time scales of reservations might be different (long living 2) The time scales of reservations might be different (long living
reservations of aggregates, rarer re-negotiation). reservations of aggregates, rarer re-negotiation).
3) The specification of the traffic (amount of traffic), a 3) The specification of the traffic (amount of traffic), a
particular QoS is guaranteed for, needs to be changed. E.g., in case particular QoS is guaranteed for, needs to be changed. E.g., in case
additional flows are added to the aggregate, the traffic additional flows are added to the aggregate, the traffic
Brunner, et al. Informational [Page 33]
Requirements for QoS Signaling Protocols May 2002
specification of the flow needs to be added if it is not already specification of the flow needs to be added if it is not already
included in the aggregates specification. included in the aggregates specification.
4) The flow specification is more complex including network 4) The flow specification is more complex including network
addresses and sets of different address for the source as well as addresses and sets of different address for the source as well as
for the destination of the flow. for the destination of the flow.
8.7 Scenario: QoS reservation/negotiation over administrative Requirements for QoS Signaling Protocols July 2002
10.7 Scenario: QoS reservation/negotiation over administrative
boundaries boundaries
Signaling between two or more core networks to provide QoS is Signaling between two or more core networks to provide QoS is
handled in this scenario. This might also include access to core handled in this scenario. This might also include access to core
signaling over administrative boundaries. Compared to the previous signaling over administrative boundaries. Compared to the previous
one it adds the case, where the two networks are not in the same one it adds the case, where the two networks are not in the same
administrative domain. Basically, it is the inter-domain/inter administrative domain. Basically, it is the inter-domain/inter
provider signaling which is handled in here. provider signaling which is handled in here.
The domain boundary is the critical issue to be resolved. Which as The domain boundary is the critical issue to be resolved. Which as
skipping to change at line 1879 skipping to change at page 39, line 39
2) Additionally, as in scenario 4, signaling most likely is based on 2) Additionally, as in scenario 4, signaling most likely is based on
aggregates, with all the issues raise there. aggregates, with all the issues raise there.
3) Authorization: It is critical that the QoS initiator is 3) Authorization: It is critical that the QoS initiator is
authorized to perform a QoS path setup. authorized to perform a QoS path setup.
4) Accountability: It is important to notice that signaling might be 4) Accountability: It is important to notice that signaling might be
used as an entity to charge money for, therefore the interoperation used as an entity to charge money for, therefore the interoperation
with accounting needs to be available. with accounting needs to be available.
8.8 Scenario: QoS signaling between PSTN gateways and backbone routers 10.8 Scenario: QoS signaling between PSTN gateways and backbone
routers
A PSTN gateway (i.e., host) requires information from the network A PSTN gateway (i.e., host) requires information from the network
regarding its ability to transport voice traffic across the network. regarding its ability to transport voice traffic across the network.
The voice quality will suffer due to packet loss, latency and The voice quality will suffer due to packet loss, latency and
jitter. Signaling is used to identify and admit a flow for which jitter. Signaling is used to identify and admit a flow for which
these impairments are minimized. In addition, the disposition of these impairments are minimized. In addition, the disposition of
the signaling request is used to allow the PSTN GW to make a call the signaling request is used to allow the PSTN GW to make a call
routing decision before the call is actually accepted and delivered routing decision before the call is actually accepted and delivered
to the final destination. to the final destination.
PSTN gateways may handle thousands of calls simultaneously and there PSTN gateways may handle thousands of calls simultaneously and there
may be hundreds of PSTN gateways in a single provider network. These may be hundreds of PSTN gateways in a single provider network. These
numbers are likely to increase as the size of the network increases. numbers are likely to increase as the size of the network increases.
The point being that scalability is a major issue. The point being that scalability is a major issue.
Brunner, et al. Informational [Page 34]
Requirements for QoS Signaling Protocols May 2002
There are several ways that a PSTN gateway can acquire assurances There are several ways that a PSTN gateway can acquire assurances
that a network can carry its traffic across the network. These that a network can carry its traffic across the network. These
include: include:
1. Over-provisioning a high availability network. 1. Over-provisioning a high availability network.
Requirements for QoS Signaling Protocols July 2002
2. Handling admission control through some policy server 2. Handling admission control through some policy server
that has a global view of the network and its resources. that has a global view of the network and its resources.
3. Per PSTN GW pair admission control. 3. Per PSTN GW pair admission control.
4. Per call admission control (where a call is defined as 4. Per call admission control (where a call is defined as
the 5 tuple used to carry a single RTP flow). the 5 tuple used to carry a single RTP flow).
Item 1 requires no signaling at all and is therefore outside the Item 1 requires no signaling at all and is therefore outside the
scope of this working group. scope of this working group.
Item 2 is really a better informed version of 1, but it is also Item 2 is really a better informed version of 1, but it is also
skipping to change at line 1952 skipping to change at page 40, line 56
with an optional authentication process, possibly involving an with an optional authentication process, possibly involving an
external policy server. Note that the relationship between the PSTN external policy server. Note that the relationship between the PSTN
GW and the policy server and the routers and the policy server is GW and the policy server and the routers and the policy server is
outside the scope of NSIS. The edge router then admits the flow into outside the scope of NSIS. The edge router then admits the flow into
the core of the network, possibly using some aggregation technique. the core of the network, possibly using some aggregation technique.
At the interior nodes, the NSIS host-to-host signaling should either At the interior nodes, the NSIS host-to-host signaling should either
be ignored or invisible as the Edge router performed the admission be ignored or invisible as the Edge router performed the admission
control decision to some aggregate. control decision to some aggregate.
Brunner, et al. Informational [Page 35]
Requirements for QoS Signaling Protocols May 2002
At the inter-provider router (i.e., border node), again the NSIS At the inter-provider router (i.e., border node), again the NSIS
host-to-host signaling should either be ignored or invisible as the host-to-host signaling should either be ignored or invisible as the
Edge router has performed an admission control decision about an Edge router has performed an admission control decision about an
aggregate across a carrier network. aggregate across a carrier network.
8.9 PSTN trunking gateway Requirements for QoS Signaling Protocols July 2002
10.9 Scenario: PSTN trunking gateway
One of the use cases for the NSIS signaling protocol is the scenario One of the use cases for the NSIS signaling protocol is the scenario
of interconnecting PSTN gateways with an IP network that supports of interconnecting PSTN gateways with an IP network that supports
QoS. QoS.
Four different scenarios are considered here. Four different scenarios are considered here.
1. In-band QoS signaling is used. In this case the Media Gateway 1. In-band QoS signaling is used. In this case the Media Gateway
(MG) will be acting as the QoS Initiator and the Edge Router (MG) will be acting as the QoS Initiator and the Edge Router
(ER) will be the QoS Controller. Hence, the ER should do (ER) will be the QoS Controller. Hence, the ER should do
admission control (into pre-provisioned traffic trunks) for the admission control (into pre-provisioned traffic trunks) for the
individual traffic flows. This scenario is not further individual traffic flows. This scenario is not further
skipping to change at line 2008 skipping to change at page 41, line 55
: / / +-----+ \ \ : / / +-----+ \ \
: / / | NMS | \ \ : / / | NMS | \ \
: / | +-----+ | \ : / | +-----+ | \
: : | | : : : | | :
+--------------+ +----+ | bandwidth pipe (SLS) | +----+ +--------------+ +----+ | bandwidth pipe (SLS) | +----+
| PSTN network |--| MG |--|ER|======================|ER|-| MG |-- | PSTN network |--| MG |--|ER|======================|ER|-| MG |--
+--------------+ +----+ \ / +----+ +--------------+ +----+ \ / +----+
\ QoS network / \ QoS network /
+-------------------+ +-------------------+
Brunner, et al. Informational [Page 36]
Requirements for QoS Signaling Protocols May 2002
Figure 1: PSTN trunking gateway scenario Figure 1: PSTN trunking gateway scenario
In the third scenario, the voice provider does not lease traffic In the third scenario, the voice provider does not lease traffic
trunks in the network. Another entity may lease traffic trunks and trunks in the network. Another entity may lease traffic trunks and
may use a QoS Controller to do per-flow admission control. In this may use a QoS Controller to do per-flow admission control. In this
case the NSIS signaling is used between the MGC and the QoS case the NSIS signaling is used between the MGC and the QoS
Requirements for QoS Signaling Protocols July 2002
Controller, which is a separate box here. Hence, the MGC acts only Controller, which is a separate box here. Hence, the MGC acts only
as a QoS Initiator. This scenario is depicted in figure 2. as a QoS Initiator. This scenario is depicted in figure 2.
+-------------+ ISUP/SIGTRAN +-----+ +-----+ +-------------+ ISUP/SIGTRAN +-----+ +-----+
| SS7 network |---------------------| MGC |--------------| SS7 | | SS7 network |---------------------| MGC |--------------| SS7 |
+-------------+ +-------+-----+---------+ +-----+ +-------------+ +-------+-----+---------+ +-----+
: / : \ : / : \
: / +-----+ \ : / +-----+ \
: / | QC | \ : / | QC | \
: / +-----+ \ : / +-----+ \
skipping to change at line 2051 skipping to change at page 42, line 40
In the fourth scenario multiple transport domains are involved. In In the fourth scenario multiple transport domains are involved. In
the originating network either the MGC may have an overview on the the originating network either the MGC may have an overview on the
resources of the overlay network or a separate QoS Controller will resources of the overlay network or a separate QoS Controller will
have the overview. Hence, depending on this either the MGC or the have the overview. Hence, depending on this either the MGC or the
QoS Controller of the originating domain will contact the QoS QoS Controller of the originating domain will contact the QoS
Controller of the next domain. The MGC always acts as a QoS Controller of the next domain. The MGC always acts as a QoS
Initiator and may also be acting as a QoS Controller in the first Initiator and may also be acting as a QoS Controller in the first
domain. domain.
8.10 Scenario: Application request end-to-end QoS path from the 10.10 Scenario: Application request end-to-end QoS path from the
network network
This is actually the most easy case, nevertheless might be most This is actually the easiest case, nevertheless might be most often
often used in terms of number of users. So multimedia application used in terms of number of users. So multimedia application requests
requests a guaranteed service from an IP network. We assume here a guaranteed service from an IP network. We assume here that the
that the application is somehow able to specify the network service. application is somehow able to specify the network service. The
The characteristics here are that many hosts might do it, but that characteristics here are that many hosts might do it, but that the
the requested service is low capacity (bounded by the access line). requested service is low capacity (bounded by the access line).
Additionally, we assume no mobility and standard devices. Additionally, we assume no mobility and standard devices.
Brunner, et al. Informational [Page 37] 10.11 Scenario: QOS for Virtual Private Networks
Requirements for QoS Signaling Protocols May 2002
9 Acknowledgments In a Virtual Private Network (VPN) a variety of tunnels might be
used between its edges. These tunnels could be for example, IP-Sec,
GRE, and IP-IP. One of the most significant issues in VPNs is
related to how a flow is identified and what quality a flow gets. A
flow identification might consist among others of the transport
Requirements for QoS Signaling Protocols July 2002
Quite a number of people have been involved in the discussion of the protocol port numbers. In an IP-Sec tunnel this will be problematic
draft, adding some ideas, requirements, etc. We list them without a since the transport protocol information is encrypted.
guarantee on completeness: Changpeng Fan (Siemens), Krishna Paul
(NEC), Maurizio Molina (NEC), Mirko Schramm (Siemens), Andreas
Schrader (NEC), Hannes Hartenstein (NEC), Ralf Schmitz (NEC),
Juergen Quittek (NEC), Morihisa Momona (NEC), Holger Karl (Technical
University Berlin), Xiaoming Fu (Technical University Berlin), Hans-
Peter Schwefel (Siemens), Mathias Rautenberg (Siemens), Christoph
Niedermeier (Siemens), Andreas Kassler (University of Ulm), Ilya
Freytsis.
Some text and/or ideas for text, requirements, scenarios have been There are two types of L3 VPNs, distinguished by where the endpoints
taken from a draft written by the following authors: David Partain of the tunnels exist. The endpoints of the tunnels may either be on
(Ericsson), Anders Bergsten (Telia Research), Marc Greis (Nokia), the customer (CPE) or the provider equipment or provider edge (PE).
Georgios Karagiannis (Ericsson), Jukka Manner (University of
Helsinki), Ping Pan (Juniper), Vlora Rexhepi (Ericsson), Lars
Westberg (Ericsson), Haihong Zheng (Nokia). Some of those have
actively contributed new text to the draft as well.
Another draft impacting this draft has been written by Sven Van den Virtual Private networks are also likely to request bandwidth or
Bosch, Maarten Buchli, and Danny Goderis. These people contributed other type of service in addition to the premium services the PSTN
also with new text. GW are likely to use.
10 Author's Addresses Tunnel end points at the Customer premises
Marcus Brunner (Editor) When the endpoints are the CPE, the CPE may want to signal across
NEC Europe Ltd. the public IP network for a particular amount of bandwidth and QoS
Network Laboratories for the tunnel aggregate. Such signaling may be useful when a
Adenauerplatz 6 customer wants to vary their network cost with demand, rather than
D-69115 Heidelberg paying a flat rate. Such signaling exists between the two CPE
Germany routers. Intermediate access and edge routers perform the same exact
E-Mail: brunner@ccrle.nec.de (contact) call admission control, authentication and aggregation functions
performed by the corresponding routers in the PSTN GW scenario with
the exception that the endpoints are the CPE tunnel endpoints rather
than PSTN GWs and the 5-tuple used to describe the RTP flow is
replaced with the corresponding flow spec to uniquely identify the
tunnels. Tunnels may be of any variety (e.g. IP-Sec, GRE, IP-IP).
Robert Hancock, Eleanor Hepworth In such a scenario, NSIS would actually allow partly for customer
Roke Manor Research Ltd managed VPNs, which means a customer can setup VPNs by subsequent
Romsey, Hants, SO51 0ZN NSIS signaling to various end-point. Plus the tunnel end-points are
United Kingdom not necessarily bound to an application. The customer administrator
E-Mail: [robert.hancock|eleanor.hepworth]@roke.co.uk might be the one triggering NSIS signaling.
Cornelia Kappler Tunnel end points at the provider premises
Siemens AG
Berlin 13623
Germany
E-Mail: cornelia.kappler@icn.siemens.de
Hannes Tschofenig In the case were the tunnel end-points exist on the provider edge,
Siemens AG requests for bandwidth may be signaled either per flow, where a flow
Otto-Hahn-Ring 6 is defined from a customers address space, or between customer
81739 Munchen sites.
Germany
Email: Hannes.Tschofenig@mchp.siemens.de
Brunner, et al. Informational [Page 38] In the case of per flow signaling, the PE router must map the
Requirements for QoS Signaling Protocols May 2002 bandwidth request to the tunnel carrying traffic to the destination
specified in the flow spec. Such a tunnel is a member of an
aggregate to which the flow must be admitted. In this case, the
operation of admission control is very similar to the case of the
PSTN GW with the additional level of indirection imposed by the VPN
tunnel. Therefore, authentication, accounting and policing may be
required on the PE router.
In the case of per site signaling, a site would need to be
identified. This may be accomplished by specifying the network
serviced at that site through an IP prefix. In this case, the
admission control function is performed on the aggregate to the PE
router connected to the site in question.
Requirements for QoS Signaling Protocols July 2002
Full Copyright Statement Full Copyright Statement
Copyright (C) The Internet Society (2000). All Rights Reserved. Copyright (C) The Internet Society (2000). All Rights Reserved.
This document and translations of it may be copied and furnished to This document and translations of it may be copied and furnished to
others, and derivative works that comment on or otherwise explain it others, and derivative works that comment on or otherwise explain it
or assist in its implementation may be prepared, copied, published or assist in its implementation may be prepared, copied, published
and distributed, in whole or in part, without restriction of any and distributed, in whole or in part, without restriction of any
kind, provided that the above copyright notice and this paragraph are kind, provided that the above copyright notice and this paragraph are
included on all such copies and derivative works. However, this included on all such copies and derivative works. However, this
document itself may not be modified in any way, such as by removing document itself may not be modified in any way, such as by removing
the copyright notice or references to the Internet Society or other the copyright notice or references to the Internet Society or other
Internet organizations, except as needed for the purpose of Internet organizations, except as needed for the purpose of
skipping to change at line 2148 skipping to change at page 44, line 34
revoked by the Internet Society or its successors or assigns. revoked by the Internet Society or its successors or assigns.
This document and the information contained herein is provided on an This document and the information contained herein is provided on an
"AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING
TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDIN TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDIN
BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION
HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
Open Issues/To Dos Open Issues/To Dos
1) (OPEN) add Scenarios
Do we need to add, remove, or change the scenarios?
- added scenario on QoS signalling between PSTN gateways and
backbone routers
- added: Application request end-to-end QoS path from the network
We can what ever scenario we want. The more the better to understand
the issues. Nevertheless, we have to take care that we are future
prove as well.
2) (OPEN) Sender/receiver initiation 2) (OPEN) Sender/receiver initiation
What is the requirement concerning data sender or data receiver or What is the requirement concerning data sender or data receiver or
both to initiate a QoS request. both to initiate a QoS request.
Terminology text added Terminology text added
open issue, what is a potential req (currently we say "both must be open issue, what is a potential req (currently we say "both must be
possible") possible")
Proposals: Proposals:
1)should be optimized for sender initiated 1)should be optimized for sender initiated
2) remove the requirement, because it is not relevant if we allow 2) remove the requirement, because it is not relevant if we allow
for third party QoS initiators for third party QoS initiators
3) SHOULD support sender initiated, MAY support reciever initiated 3) SHOULD support sender initiated, MAY support reciever initiated
Issues: Issues:
Brunner, et al. Informational [Page 39]
Requirements for QoS Signaling Protocols May 2002
- does it matter who pays? - does it matter who pays?
- for sender initiated, can we support implicit signaling - for sender initiated, can we support implicit signaling
(bundling the QoS requests with other signaling - registration, (bundling the QoS requests with other signaling - registration,
etc.)? etc.)?
- For reciever initiated, do we need protection against spamming - - For reciever initiated, do we need protection against spamming -
how do we protect against unwanted changes? how do we protect against unwanted changes?
Requirements for QoS Signaling Protocols July 2002
4) (OPEN) MUSTs, SHOULDs, MAY needs discussion
28) (OPEN) new requirement on "asynchronous events from the network"
The content of the message might be very service specific, but the
protocol support for asynchronous events from the network might be a
valuable requirement. We have something about notification in case
of errors/failures.
Asynchronous notification of QoS Initiator, Controller, Receiver,
there are security issues related. Basically, an ownership issue.
Nevertheless, an asynch notifcation in case of an error, network
failure etc. is specifically in areas, where longer lived sessions
are setup, essential in order to notify upper layers.
44) (OPEN) req resource availability info on request come back to it
as soon as we have a more clear idea about service description issue
53) (OPEN) Error handling
Comments:
1) notification of user in case of unrecoverable errors (has been
done by notification requirement, or will be done by asynch
notification, issue 43)
A description of both types of errors (recoverable, unrecoverable)
are listed in Section 5.3.4.
2) hop-by-hop? OR right to the end?
3) What is potential value to notify about recoverable errors?
Proposal: not hop by hop, but QoS controller to QoS initiator
59) (OPEN) add req: ability to deal with severe congestion (req
5.3.4 of draft-partain-..-00
issues are:
- occurs in a highly utilised network and if it is not solved very
fast then the network performance will quickly collapse
- deos it belong to failure recovery (I would assume from a service
point of view this is failure
- hop by hop problem (issue from Jorge)
- What difference does it make (from the QoS perspective) if the
provided QoS degraded due to hardware failure on a device or due to
congestion caused by failures on some other devices? What is
required from the protocol is to signal this failure to other
participants (QCs or QI) in the hope that they can do something
meaningful (e.g. re-routing) to correct the problem or tear down the
flow.
65) (OPEN) Request to add req: Unexpected situations and error
restistance
An NSIS protocol must define behaviour of NSIS signaling units
during unexpected situations. Unexpected situtions are unknown
Requirements for QoS Signaling Protocols July 2002
messages, parameters and parameter settings as well as receiption of
unexpected messages (e.g. a "Reservation Confirmation" without prior
"Reservation Request").
Related to Open issues (53) and requirement 5.3.4.
This requirement is emphasizing to many details that might not be
necessary
Req 5.3.4 refers to behaviour in the case of problems in the data
plane. My suggestion here is about unexpected events/errors in the
control plane. If you think that this point carries to many details,
let's split it up in several individual requirements.
72) (OPEN) request to add "Error notification and error location"
"An NSIS signaling node rejecting or releasing a reservation must
indicate its identity. NSIS signalling should indicate why a
requested resource is not or no longer available. "
Compared to 5.3.4 this is about problems on the control plane
Closed Issues
1) (CLOSED) add Scenarios
Do we need to add, remove, or change the scenarios?
- added scenario on QoS signalling between PSTN gateways and
backbone routers
- added: Application request end-to-end QoS path from the network
- added VPN scenario
We can add what ever scenario we want. The more the better to
understand the issues. Nevertheless, we have to take care that we
are future prove as well.
3) (CLOSED) Draft organization 3) (CLOSED) Draft organization
The proposed changes include The proposed changes include
- put all the scenarios into an appendix - put all the scenarios into an appendix
- In Section 6 add text describing 3 different "parts of the - In Section 6 add text describing 3 different "parts of the
network" network"
-Host to first hop -Host to first hop
-access network -access network
-core networks -core networks
better names are welcome, but I don't want to be religious about better names are welcome, but I don't want to be religious about
it it
- Prioritize the requirements according to the "parts of the - Prioritize the requirements according to the "parts of the
network" (This means the the tables in Section 6 of the current network" (This means the the tables in Section 6 of the current
draft will get three colums with the MUST, SHOULDs, and MAYs for draft will get three colums with the MUST, SHOULDs, and MAYs for
each requirement each requirement
4) (OPEN) MUSTs, SHOULDs, MAY needs discussion
5) (CLOSED) Framework text. 5) (CLOSED) Framework text.
The figures have been removed, because they seamed to be misleading. The figures have been removed, because they seamed to be misleading.
the text has been revisited. I regard the issue closed until we have the text has been revisited. I regard the issue closed until we have
a clear picture about what the NSIS framework draft is about. a clear picture about what the NSIS framework draft is about.
Requirements for QoS Signaling Protocols July 2002
6) (CLOSED) The requirement organization 6) (CLOSED) The requirement organization
I heard some voices on the list that the grouping should be more I heard some voices on the list that the grouping should be more
along the lines of host-to-edge, edge to edge etc. along the lines of host-to-edge, edge to edge etc.
So far I have not changed it, because I though that the requirements So far I have not changed it, because I though that the requirements
heavily depend on the scenario we are looking at. heavily depend on the scenario we are looking at.
closed, by the change in the draft organisation (issue 3) closed, by the change in the draft organisation (issue 3)
7) (OPEN) Hemant Chaskar: Section 3.1, items 1) Handoff decision and 7) (CLOSED) Hemant Chaskar: Section 3.1, items 1) Handoff decision
2) Trigger sources: The handoff decision and trigger sources should and 2) Trigger sources: The handoff decision and trigger sources
be out of scope of NSIS. NSIS should rather focus only on should be out of scope of NSIS. NSIS should rather focus only on
"establishing" QoS along the packet path after handoff. "establishing" QoS along the packet path after handoff.
needs more WG discussion, potentially even cross-WG added exclusion
8) (OPEN) bi-directional data path setup with one QoS request 8) (CLOSED) bi-directional data path setup with one QoS request
I have not seen consensus on whether to require bi-directional data I have not seen consensus on whether to require bi-directional data
path setup with QoS. path setup with QoS.
Brunner, et al. Informational [Page 40]
Requirements for QoS Signaling Protocols May 2002
Q: How can we actually perform bi-directional reservations when the Q: How can we actually perform bi-directional reservations when the
forward and reverse paths are not reciprocal, with respect to forward and reverse paths are not reciprocal, with respect to
routing topology and routing policy of network domains between routing topology and routing policy of network domains between
sender and receiver? sender and receiver?
A: bi-directional data path setup does not need to use the same A: bi-directional data path setup does not need to use the same
return path as the forwarding path. The only requirement to achieve return path as the forwarding path. The only requirement to achieve
a bi-directional reservation is that the sender for the forwarding a bi-directional reservation is that the sender for the forwarding
path is also the receiver for the return path and that the receiver path is also the receiver for the return path and that the receiver
for the forwarding path is also the sender for the return path. for the forwarding path is also the sender for the return path.
- The need to ensure that the return path is the same as the - The need to ensure that the return path is the same as the
forwarding path is one of the problems with RSVP, particularly in a forwarding path is one of the problems with RSVP, particularly in a
mobile environment. mobile environment.
added some explanations that we do not require the same path, and
that the goal is an optimization of the setup delay
9) (CLOSED) Potential requirement: must be implementable in user 9) (CLOSED) Potential requirement: must be implementable in user
space (on end hosts) space (on end hosts)
has not been included in the req list because it seams to be has not been included in the req list because it seams to be
implementation specific. implementation specific.
10) (CLOSED) Potential requirement: must provide support for 10) (CLOSED) Potential requirement: must provide support for
globally defined services as well as private services (Ruediger) globally defined services as well as private services (Ruediger)
replaced by issue 17 and 18, closed replaced by issue 17 and 18, closed
11) (CLOSED) Potential requirement: Flexibility in the granularity 11) (CLOSED) Potential requirement: Flexibility in the granularity
of reservation (I don't remember who brought it up, but I assume it of reservation (I don't remember who brought it up, but I assume it
refers to the flexibility in terms of what size the flow has. Where refers to the flexibility in terms of what size the flow has. Where
size can be bandwidth etc.) size can be bandwidth etc.)
Requirements for QoS Signaling Protocols July 2002
The assumption that QoS classes as well as service definitions are The assumption that QoS classes as well as service definitions are
out of scope for this draft, also the flexibility is. out of scope for this draft, also the flexibility is.
12) (CLOSED) text replacing scalability reqs 12) (CLOSED) text replacing scalability reqs
"The nsis architecture should give the ability to constrain the load "The nsis architecture should give the ability to constrain the load
(CPU load, memory space, signaling bandwidth consumption and (CPU load, memory space, signaling bandwidth consumption and
signaling intensity) on devices where it is needed. This can be signaling intensity) on devices where it is needed. This can be
achieved by many different methods, for example message aggregation, achieved by many different methods, for example message aggregation,
skipping to change at line 2287 skipping to change at page 48, line 28
Editor: added the draft text, but did not remove scalability reqs Editor: added the draft text, but did not remove scalability reqs
13) (CLOSED) add operator req "Ability to assign transport quality 13) (CLOSED) add operator req "Ability to assign transport quality
to signaling messages" to signaling messages"
"The nsis architecture should allow the network operator to assign "The nsis architecture should allow the network operator to assign
the nsis protocol messages a certain transport quality. As signaling the nsis protocol messages a certain transport quality. As signaling
opens up for possible denial-of-service attacks, this requirement opens up for possible denial-of-service attacks, this requirement
gives the network operator a mean, but also the obligation, to gives the network operator a mean, but also the obligation, to
trade-off between signaling latency and the impact (from the trade-off between signaling latency and the impact (from the
Brunner, et al. Informational [Page 41]
Requirements for QoS Signaling Protocols May 2002
signaling messages) on devices within his/her network. From protocol signaling messages) on devices within his/her network. From protocol
design this requirement states that the protocol messages should be design this requirement states that the protocol messages should be
detectable, at least where the control and assignment of the detectable, at least where the control and assignment of the
messages priority is done." messages priority is done."
text has been added text has been added
14) (OPEN, dependend on resolution of bi-directional) proposal to 14) (CLOSED) proposal to add "support grouping of microflows
add "support grouping of microflows (possibly only for feedback)" (possibly only for feedback)"
"As a consequence of the optimization for the interactive multimedia "As a consequence of the optimization for the interactive multimedia
services, the signaling should allow one unique request for several services, the signaling should allow one unique request for several
micro flows having the same origination and destination IP micro flows having the same origination and destination IP
addresses. This is usually the case for multimedia SIP calls where addresses. This is usually the case for multimedia SIP calls where
the voice and video micro flows follow the same path. This grouping the voice and video micro flows follow the same path. This grouping
of requests allows optimization of the QoS processing. Note that of requests allows optimization of the QoS processing. Note that
this may be detrimental for the call setup time. The use of grouping this may be detrimental for the call setup time. The use of grouping
for microflows may be restricted to teardown and/or notification for microflows may be restricted to teardown and/or notification
messages when call setup time is a concern." messages when call setup time is a concern."
open issue: first resolve the bi-directional issue which is somewhat
related, because it seams to be an optimization as well
Should not be restrict to teardown and/or notification, it might be Should not be restrict to teardown and/or notification, it might be
useful also for the procedure that refreshes reservation states useful also for the procedure that refreshes reservation states
added that requirement.
15) (CLOSED) Support for preemption of sessions 15) (CLOSED) Support for preemption of sessions
-might play into the fault/ error handling case -might play into the fault/ error handling case
-is regarded as service-specific, whether existing sessions can be -is regarded as service-specific, whether existing sessions can be
pre-empted pre-empted
Conclusion: it is network policy to determine how to do pre-emption, Conclusion: it is network policy to determine how to do pre-emption,
not a protocol issue. not a protocol issue.
16) (OPEN) Req: 5.1.9 change provisioning into better term, since Requirements for QoS Signaling Protocols July 2002
16) (CLOSED) Req: 5.1.9 change provisioning into better term, since
different people understand different thing with provisioning different people understand different thing with provisioning
open action for Anders we did not find a better word
17) (CLOSED) add assumption that QoS classes/service definitions are 17) (CLOSED) add assumption that QoS classes/service definitions are
already known to all the parties involved in signaling before hand already known to all the parties involved in signaling before hand
(before a signalling session even starts (before a signalling session even starts
added text in Section 4.1 added text in Section 4.1
18) (CLOSED) add exclusion of methods, protocols, and ways to 18) (CLOSED) add exclusion of methods, protocols, and ways to
express QoS express QoS
Even so, this might be covered by saying that we are independent of Even so, this might be covered by saying that we are independent of
QoS classes and service description etc. (see issue 17), I added two QoS classes and service description etc. (see issue 17), I added two
points to the exclusion Section 4.2. points to the exclusion Section 4.2.
Implications: issue 20, 23, Implications: issue 20, 23,
19) (CLOSED) remove req 5.2.5 IP fragmentation 19) (CLOSED) remove req 5.2.5 IP fragmentation
Brunner, et al. Informational [Page 42]
Requirements for QoS Signaling Protocols May 2002
20) (CLOSED) remove req 5.3.2 Ability to signal life-time of a 20) (CLOSED) remove req 5.3.2 Ability to signal life-time of a
reservation reservation
is regarded service-specific therefore part of the service is regarded service-specific therefore part of the service
description description
added some reservation life time text service description assumption added some reservation life time text service description assumption
text and removed the req text and removed the req
21) (CLOSED) remove req 5.5.4 Aggregation method specification 21) (CLOSED) remove req 5.5.4 Aggregation method specification
skipping to change at line 2380 skipping to change at page 50, line 4
removed removed
23) (CLOSED) remove 5.5.3 Simple mapping to lower-layer QoS 23) (CLOSED) remove 5.5.3 Simple mapping to lower-layer QoS
provisioning parameters provisioning parameters
this heavily depends on service definition and therefore is out of this heavily depends on service definition and therefore is out of
scope of this document scope of this document
removed removed
Requirements for QoS Signaling Protocols July 2002
24) (CLOSED) Replacing req 5.3.6 "Feedback about the actually 24) (CLOSED) Replacing req 5.3.6 "Feedback about the actually
received level of QoS guarantees" with two requirements: 1) the received level of QoS guarantees" with two requirements: 1) the
feedback of a request MUST include yes and no (MUST respond yes or feedback of a request MUST include yes and no (MUST respond yes or
no) 2) in case of no it MAY include an opaque service-specific no) 2) in case of no it MAY include an opaque service-specific
information about what would be possible information about what would be possible
It is still only one requirement, but the text has been replaced. It is still only one requirement, but the text has been replaced.
25) (CLOSED) remove req 5.10.3 Combination with Mobility management 25) (CLOSED) remove req 5.10.3 Combination with Mobility management
However the integration should not be a priori excluded, there is However the integration should not be a priori excluded, there is
explicitly no statemant about independence of mobility management. explicitly no statemant about independence of mobility management.
There is more discussion for the mobility case needed anyway. There is more discussion for the mobility case needed anyway.
26) (OPEN) interaction of NSIS with seamoby (context transfer and 26) (CLOSED) interaction of NSIS with seamoby (context transfer and
CAR discovery) CAR discovery)
27) (CLOSED) remove req 5.5.10 QoS conformance specification added requirement, that NSIS should interwork with seamoby protocols
Brunner, et al. Informational [Page 43]
Requirements for QoS Signaling Protocols May 2002
27) (CLOSED) remove req 5.5.10 QoS conformance specification
Motivation: this heavily depends on the service definition and is Motivation: this heavily depends on the service definition and is
therefore out of scope therefore out of scope
removed removed
28) (OPEN) new requirement on "asynchronous events from the network" 29) (CLOSED) NSIS in case of handovers
issue 26, mentions that NSIS should interwork with handoffs
The content of the message might be very service specific, but the
protocol support for asynchronous events from the network might be a
valuable requirement. We have something about notification in case
of errors/failures.
29) (OPEN) NSIS in case of handovers
The whole mobility area needs to be defined
30) (CLOSED) remove 5.1.7 Avoid modularity with large overhead (in 30) (CLOSED) remove 5.1.7 Avoid modularity with large overhead (in
various dimensions) various dimensions)
removed because it seams to be obvious removed because it seams to be obvious
31) (CLOSED) remove 5.1.8 Possibility to use the signaling protocol 31) (CLOSED) remove 5.1.8 Possibility to use the signaling protocol
for existing local technologies for existing local technologies
It is contradictory to 5.1.9 and the intention behind the It is contradictory to 5.1.9 and the intention behind the
skipping to change at line 2441 skipping to change at page 51, line 5
32) (CLOSED) add assumption: there are means for discovery of nsis 32) (CLOSED) add assumption: there are means for discovery of nsis
entities in order to know the signaling peers (solutions include entities in order to know the signaling peers (solutions include
static configuration, or automatically discovered etc.) static configuration, or automatically discovered etc.)
33) (CLOSED) add req " highest possible network utilization" 33) (CLOSED) add req " highest possible network utilization"
"There are networking environments that require high network "There are networking environments that require high network
utilization for various reasons, and the signaling protocol should utilization for various reasons, and the signaling protocol should
to its best ability support high resource utilization while to its best ability support high resource utilization while
maintaining appropriate QoS. maintaining appropriate QoS.
Requirements for QoS Signaling Protocols July 2002
In networks where resources are very expensive (as is the case for In networks where resources are very expensive (as is the case for
many wireless networks), efficient network utilization is of many wireless networks), efficient network utilization is of
critical financial importance. On the other hand there are other critical financial importance. On the other hand there are other
parts of the network where high utilization is not required. parts of the network where high utilization is not required.
" "
req added req added
34) (CLOSED)_difference between "UMTS access scenario" "cellular 34) (CLOSED)_difference between "UMTS access scenario" "cellular
network scenario", and "Wired part of wireless network" (Section network scenario", and "Wired part of wireless network" (Section
8.2, 8.3, and 8.4) 8.2, 8.3, and 8.4)
all three are included. all three are included.
The only common point between the three scenarios is that they are The only common point between the three scenarios is that they are
related to cellular networks. Section 8.4 is introducing the related to cellular networks. Section 8.4 is introducing the
scenario used in the radio access network of cellular networks. scenario used in the radio access network of cellular networks.
Brunner, et al. Informational [Page 44]
Requirements for QoS Signaling Protocols May 2002
Sections 8.2 and Section 8.3 are discussing other parts of the Sections 8.2 and Section 8.3 are discussing other parts of the
cellular network. cellular network.
35) (CLOSED) difference between the two PSTN gateway scenarios 35) (CLOSED) difference between the two PSTN gateway scenarios
(Section 8.8 and 8.9) (Section 8.8 and 8.9)
currently both are included, they might be merged, sionce one seams currently both are included, they might be merged, sionce one seams
to be more general than the other to be more general than the other
36) (OPEN) req "Independence of reservation identifier" 36) (CLOSED) req "Independence of reservation identifier"
issue here is that this might only be valuable in mobile issue here is that this might only be valuable in mobile
environments, and complicate the protocol for other environemnts. environments, and complicate the protocol for other environments.
there are related issues (37,38, there are related issues (37,38,
37) (OPEN) ownership of a reservation 37) (CLOSED) ownership of a reservation
The issue here is that a known party owns reservations done in the The issue here is that a known party owns reservations done in the
network. (which might include that the party also pays). The network. (which might include that the party also pays). The
question arose who is allowed to tear-down, receive asynchronous question arose who is allowed to tear-down, receive asynchronous
notifications in case of network initiated tear-down, etc. notifications in case of network initiated tear-down, etc.
This also relates to how certain service granted is This also relates to how certain service granted is
named/identified. named/identified.
38) (OPEN) definition of security threats req 5.8.9 added (renamed)
39) (OPEN) simplify security requirements section 38) (CLOSED) definition of security threats
handled in draft-tschofenig-nsis-threats-00.txt
40) (OPEN) add mobility related requirements 39) (CLOSED) simplify security requirements section
done
40) (CLOSED) add mobility related requirements
we have some mobility related requirements, but do not need to add
more
Requirements for QoS Signaling Protocols July 2002
41) (CLOSED) remove req 5.5.1 Mutability information on parameters 41) (CLOSED) remove req 5.5.1 Mutability information on parameters
removed because it is service-specific removed because it is service-specific
42) (OPEN) add an assumption that QoS nmonitoring is application- 42) (CLOSED) add an assumption that QoS monitoring is application-
specific and with it out of scope of the WG specific and with it out of scope of the WG (done)
43) (OPEN) asynchronous notification of QoS Initiator, Controller, 43) (CLOSED) asynchronous notification of QoS Initiator, Controller,
Receiver, there are security issues related. Basically, an ownership Receiver, there are security issues related. Basically, an ownership
issue. Nevertheless, an asynch notifcation in case of an error, issue. Nevertheless, an asynch notifcation in case of an error,
network failure etc. is specifically in areas, where longer lived network failure etc. is specifically in areas, where longer lived
sessions are setup, essential in order to notify upper layes sessions are setup, essential in order to notify upper layers,
(appluications etc. as well. applications etc. as well.
44) (OPEN) req 5.1.2 resource availability info on request come back
to it as soon as we have a more clear idea about service description
issue
45) (OPEN) 5.3.4 Possibility for automatic re-setup of resources 45) (CLOSED) 5.3.4 Possibility for automatic re-setup of resources
after recovery after recovery
- more thoughts in failure conditions potentially - more thoughts in failure conditions potentially
- better text - better text
- operation under overload - operation under overload
plays into issue 46) plays into issue 46)
Brunner, et al. Informational [Page 45] The requirement has been removed:
Requirements for QoS Signaling Protocols May 2002
46) (OPEN) we need multiple scenario for failure and recovery cases "Possibility for automatic re-setup of resources after recovery
to derive requirements. Or a list failre cases might be a start as
well.
47) (OPEN) traffic engineering and route pinning In case of a failure, the reservation can get setup again
I assume this would result in operational type of requirements automatically. It enables sort of a persistent reservation, if the
Opinions on that? QoS Initiator requests it. In scenarios where the reservations are
on a longer time scale, this could make sense to reduce the
signaling load in case of failure and recovery."
46) (CLOSED) we might need multiple scenarios for failure and
recovery cases to derive requirements. Or a list of failure cases
might be a start as well.
47) (CLOSED) traffic engineering and route pinning
added Assumption: NSIS should work with networks using standard L3
routing.
added requirement: NSIS should not be broken by networks which do
non-traditional L3 routing.
48) (CLOSED) req 5.5.5 remove Multiple levels of detail 48) (CLOSED) req 5.5.5 remove Multiple levels of detail
"The QSC should allow for multiple levels of detail in description. "The QSC should allow for multiple levels of detail in description.
(Motivation: someone interpreting the request can tune its own level (Motivation: someone interpreting the request can tune its own level
of complexity by going down to more or less levels of detail. A of complexity by going down to more or less levels of detail. A
lightweight implementation within the core could consider only the lightweight implementation within the core could consider only the
coarsest level.)" coarsest level.)"
removed, because it is service-specific removed, because it is service-specific
49) (CLOSED) remove req 5.5.9 Signaling must support quantitative, 49) (CLOSED) remove req 5.5.9 Signaling must support quantitative,
qualitative, and relative QoS specifications qualitative, and relative QoS specifications
Requirements for QoS Signaling Protocols July 2002
removed because it is service-specific removed because it is service-specific
50) (CLOSED) req 5.5.6 remove Ranges in specification 50) (CLOSED) req 5.5.6 remove Ranges in specification
The QSC should allow for specification of minimum required QoS The QSC should allow for specification of minimum required QoS
and/or desirable QoS. (Motivation: The QoS Service Classes should and/or desirable QoS. (Motivation: The QoS Service Classes should
allow for ranges to be indicated, to minimize negotiation latency allow for ranges to be indicated, to minimize negotiation latency
and suppress error notifications during handover events.) and suppress error notifications during handover events.)
skipping to change at line 2572 skipping to change at page 53, line 38
complicate the work by including all possible existing QoS signaling complicate the work by including all possible existing QoS signaling
in some form. The function will be placed in the new part if it has in some form. The function will be placed in the new part if it has
to be end-to-end, universal to all network types to be end-to-end, universal to all network types
('simple/lightweight'), or if it has to be protected by upper layer ('simple/lightweight'), or if it has to be protected by upper layer
security mechanisms.) security mechanisms.)
The point here is that the QoS technology (lower layer stuff) gets The point here is that the QoS technology (lower layer stuff) gets
re-used unchanged, and we have new signaling above it. But, in many re-used unchanged, and we have new signaling above it. But, in many
cases the local QoS technology will contain equivalent functions to cases the local QoS technology will contain equivalent functions to
the NSIS-required ones, just in a technology specific form. Examples the NSIS-required ones, just in a technology specific form. Examples
Brunner, et al. Informational [Page 46]
Requirements for QoS Signaling Protocols May 2002
of these functions would be error/QoS violation notifications, of these functions would be error/QoS violation notifications,
ability to query for resources and so on. So, there is a danger that ability to query for resources and so on. So, there is a danger that
our 'lightweight' signaling ends up trying to carry all this our 'lightweight' signaling ends up trying to carry all this
information all over again, and (even worse) that the information all over again, and (even worse) that the
initiator/controller functions have to weigh up nearly equivalent initiator/controller functions have to weigh up nearly equivalent
information coming from two directions. However, the basic problem information coming from two directions. However, the basic problem
here is that the boundary between new and re-used stuff is pretty here is that the boundary between new and re-used stuff is pretty
shaky. The requirement is trying to scope our problem (a) to shaky. The requirement is trying to scope our problem (a) to
eliminate the potential overlap, and (b) to keep the new NSIS stuff eliminate the potential overlap, and (b) to keep the new NSIS stuff
simple. simple.
However, we are aware that it is very difficult to judge what is However, we are aware that it is very difficult to judge what is
duplicated, if we want to run the protocol in various environments. duplicated, if we want to run the protocol in various environments.
52) (OPEN) New requirement: interaction with policy 52) (CLOSED) New requirement: interaction with policy
this most likely is covered by an opaque token for authentication Is part of the AAA solution or service definition, and we require
dependency on security changes that NSIS interworks with AAA
53) (OPEN) Section 5.3. Error handling
Comments:
1) notification of user in case of unrecoverable errors (has been
done by notification requirement, or will be done by asynch
notification, issue 43)
A description of both types of errors (recoverable, unrecoverable)
are listed in Section 5.3.4.
2) hop-by-hop? OR right to the end?
3) What is potential value to notify about recoverable errors?
Proposal: not hop by hop, but QoS controller to QoS initiator
54) (CLOSED) add req 5.1.17. to assumption "Identification 54) (CLOSED) add req 5.1.17. to assumption "Identification
requirement" requirement"
Requirements for QoS Signaling Protocols July 2002
assumption say that the discovery of QI, QC, QR is out-of-scope of assumption say that the discovery of QI, QC, QR is out-of-scope of
the draft the draft
55) (CLOSED) add from draft-partain-nsis-requirements-00.txt req 55) (CLOSED) add from draft-partain-nsis-requirements-00.txt req
5.2.2. Allow local QoS information exchange between two border 5.2.2. Allow local QoS information exchange between two border
nodes nodes
"The QoS signalling protocol must be able to exchange local QoS "The QoS signalling protocol must be able to exchange local QoS
information between edge nodes. Local QoS information might, for information between edge nodes. Local QoS information might, for
example, be IP addresses, severe congestion notification, example, be IP addresses, severe congestion notification,
notification of succesful or erroneous processing of QoS signalling notification of succesful or erroneous processing of QoS signalling
messages at one border node. messages at one border node.
In some domains, the NSIS QoS signalling protocol MAY carry In some domains, the NSIS QoS signalling protocol MAY carry
identification of the ingress and egress edge between the ingress- identification of the ingress and egress edge between the ingress-
egress edges. However, the identification of edges should not be egress edges. However, the identification of edges should not be
visible to the end host and only applies within one QoS visible to the end host and only applies within one QoS
administrative domain. administrative domain.
Brunner, et al. Informational [Page 47]
Requirements for QoS Signaling Protocols May 2002
" "
Comments: Comments:
- service mapping is more service-specific (layering,tunneling) - service mapping is more service-specific (layering,tunneling)
- the scenario to look at is a complicated service description -> in - the scenario to look at is a complicated service description -> in
part of the network you want to change the message to something more part of the network you want to change the message to something more
easy, and at the other end go back to the more complicated part. easy, and at the other end go back to the more complicated part.
-QI being everywhere might be enough -QI being everywhere might be enough
-and we have already a requirement saying that intermediate node -and we have already a requirement saying that intermediate node
MUST be able to add/remove domain-specific information to/from MUST be able to add/remove domain-specific information to/from
signaling messages signaling messages
56) (CLOSED) add req 5.3.1.3 of draft-partain-..-00 56) (CLOSED) add req 5.3.1.3 of draft-partain-..-00
-already added a req to the scalability section (issue ???), which -already added a req to the scalability section (issue ???), which
has been provided by Anders has been provided by Anders
57) (CLOSED) potentially better title for text from issue 56) e.g. 57) (CLOSED) potentially better title for text from issue 56) e.g.
(Űminimal impact on coreŲ) (śśminimal impact on core∆∆)
58) (CLOSED) add req 5.3.2 from draft-partain-...-00 58) (CLOSED) add req 5.3.2 from draft-partain-...-00
- the fast establishment req is handled by the low setup latency - the fast establishment req is handled by the low setup latency
req, and the scalability in handover req req, and the scalability in handover req
- added the text to the teminal mobility scenario - added the text to the teminal mobility scenario
- added text " time scale (e.g., handover in mobile environments)," - added text " time scale (e.g., handover in mobile environments),"
to req to req
59) (OPEN) add req: ability to deal with severe congestion (req
5.3.4 of draft-partain-..-00
issues are:
- occurs in a highly utilised network and if it is not solved very
fast then the network performance will quickly collapse
- deos it belong to failure recovery (I would assume from a service
point of view this is failure
- hop by hop problem (issue from Jorge)
- What difference does it make (from the QoS perspective) if the
provided QoS degraded due to hardware failure on a device or due to
congestion caused by failures on some other devices? What is
required from the protocol is to signal this failure to other
participants (QCs or QI) in the hope that they can do something
meaningful (e.g. re-routing) to correct the problem or tear down the
flow.
60) (CLOSED) add req 5.4.3. from draft-partain-...-00 "Allow 60) (CLOSED) add req 5.4.3. from draft-partain-...-00 "Allow
efficient QoS re-establishment after handover" efficient QoS re-establishment after handover"
"Handover is an essential function in wireless networks. After "Handover is an essential function in wireless networks. After
handover, QoS may need to be completely or partially re-established handover, QoS may need to be completely or partially re-established
due to route changes. The re-establishment may be requested by the due to route changes. The re-establishment may be requested by the
Requirements for QoS Signaling Protocols July 2002
mobile node itself or triggered by the access point that the mobile mobile node itself or triggered by the access point that the mobile
node is attached to. In the first case, the QoS signalling should node is attached to. In the first case, the QoS signalling should
Brunner, et al. Informational [Page 48]
Requirements for QoS Signaling Protocols May 2002
allow efficient QoS re-establishment after handover. Re- allow efficient QoS re-establishment after handover. Re-
establishment of QoS after handover should be as quick as possible establishment of QoS after handover should be as quick as possible
so that the mobile node does not experience service interruption or so that the mobile node does not experience service interruption or
QoS degradation. The re-establishment should be localized, and not QoS degradation. The re-establishment should be localized, and not
require end-to-end signalling, if possible." require end-to-end signalling, if possible."
- most likely it is already cover, please check again, whether there - most likely it is already cover, please check again, whether there
is something missing is something missing
- added it again under the mobility requiremments - added it again under the mobility requiremments
61) (OPEN) add req: 6.1.8 from draft-bucheli-...-00 on multicast 61) (CLOSED) add req: 6.1.8 from draft-bucheli-...-00 on multicast
"Multicast consideration should not impact the protocol complexity "Multicast consideration should not impact the protocol complexity
for unicast flows. Multicast support is not considered as a for unicast flows. Multicast support is not considered as a
priority, because the targeted interactive multimedia services are priority, because the targeted interactive multimedia services are
mainly unicast. For this reason, if considered in the solution, mainly unicast. For this reason, if considered in the solution,
multicast should not bring complexity in the unicast scenario." multicast should not bring complexity in the unicast scenario."
Opinions? not added
--------------------------------------------------- ---------------------------------------------------
starting from -02 version starting from -02 version
--------------------------------------------------- ---------------------------------------------------
62) (OPEN) Request to add VPN scenario 62) (CLOSED) Request to add VPN scenario
- Related to issue 1) - Related to issue 1)
- Difference of VPN scenario compared to what we already have is - Difference of VPN scenario compared to what we already have is
missing missing
added the scenario
63) (CLOSED) added Sven Van den Bosch, Maarten Buchli, and Danny 63) (CLOSED) added Sven Van den Bosch, Maarten Buchli, and Danny
Goderis to acknowledgement section. Goderis to acknowledgement section.
64) (OPEN) Request to add req: Backwards compatibility 64) (CLOSED) Request to add req: Backwards compatibility
A later version of an NSIS protocol must be backwards compatible A later version of an NSIS protocol must be backwards compatible
with earlier versions of an NSIS protocol. with earlier versions of an NSIS protocol.
65) (OPEN) Request to add req: Unexpected situations and error we can take of this if we have NSIS.
restistance
An NSIS protocol must define behaviour of NSIS signaling units
during unexpected situations. Unexpected situtions are unknown
messages, parameters and parameter settings as well as receiption of
unexpected messages (e.g. a "Reservation Confirmation" without prior
"Reservation Request").
Related to Open issues (53) and requirement 5.3.4.
This requirement is emphasizing to many details that might not be
necessary
Req 5.3.4 refers to behaviour in the case of problems in the data
plane. My suggestion here is about unexpected events/errors in the
control plane. If you think that this point carries to many details,
let's split it up in several individual requirements.
Brunner, et al. Informational [Page 49]
Requirements for QoS Signaling Protocols May 2002
66) (OPEN) Request to add req: Default behaviour 66) (CLOSED) Request to add req: Default behaviour
An NSIS protocol must define default behaviours and parameter An NSIS protocol must define default behaviours and parameter
settings wherever applicable. settings wherever applicable.
Is assumed to be normal practice.
67) (OPEN) Request to add req: Extendability 67) (CLOSED) Request to add req: Extendability
An NSIS protocol must provide means to enhance a protocol with An NSIS protocol must provide means to enhance a protocol with
future procedures, messages, parameters and parameter settings. future procedures, messages, parameters and parameter settings.
This was refering mostly to the service specific part of the This was refering mostly to the service specific part of the
protocol. protocol.
could be a part of the modularity requirement 5.1.3 could be a part of the modularity requirement 5.1.3
68) (OPEN) Request to add req: Preventation of stale state 68) (CLOSED) Request to add req: Preventation of stale state
Requirements for QoS Signaling Protocols July 2002
An NSIS signalling protocol must provide means for an NSIS signaling An NSIS signalling protocol must provide means for an NSIS signaling
unit to discover and remove local stale state. This may for example unit to discover and remove local stale state. This may for example
be done by means like soft state and periodic flooding or by a be done by means like soft state and periodic flooding or by a
polling mechanism and hard state signaling. polling mechanism and hard state signaling.
Might already be covered in other requirements, could also be that Might already be covered in other requirements, could also be that
the solutions known are solutions for different problems. I think the solutions known are solutions for different problems. I think
distributed garbage collection could also be a solution. distributed garbage collection could also be a solution.
69) (OPEN) Request to add req: Reliable Communication merged this text into requirement 5.3.2
69) (CLOSED) Request to add req: Reliable Communication
NSIS signaling procedures, connectivity between units involved in NSIS signaling procedures, connectivity between units involved in
NSIS signaling as well as the basic transport protocol used by NSIS NSIS signaling as well as the basic transport protocol used by NSIS
must provide a maximum of communication reliability. Procedures must must provide a maximum of communication reliability. Procedures must
define how an NSIS signaling systems behaves if some kind of request define how an NSIS signaling systems behaves if some kind of request
it sent stays without answer (this could require e.g. be timers, it sent stays without answer (this could require e.g. be timers,
number of message retransmits and release messages). number of message retransmits and release messages).
An NSIS signaling unit must be able to check its connectivity to an An NSIS signaling unit must be able to check its connectivity to an
adjacent NSIS signaling unit at any time (this requirement must adjacent NSIS signaling unit at any time (this requirement must
however not result in a DoS attack tool - the frequency of these however not result in a DoS attack tool - the frequency of these
checks must be limited, and flow control may be useful). checks must be limited, and flow control may be useful).
The basic transport protocol to be used between adjacent NSIS units The basic transport protocol to be used between adjacent NSIS units
must ensure message integrity and reliable transport. must ensure message integrity and reliable transport.
MUST/SHOULD ensure error- and loss free transmission of signaling MUST/SHOULD ensure error- and loss free transmission of signaling
information. information.
Do we really require this? Isn't this a soft state versus hard state Added some of the text to req 5.11.1
issue?
70) (OPEN) Request to add req: Smooth breakdown 70) (CLOSED) Request to add req: Smooth breakdown
A unit participating in NSIS signaling must no cause further damage A unit participating in NSIS signaling must no cause further damage
to other systems involved in NSIS signaling when it has to go out of to other systems involved in NSIS signaling when it has to go out of
service. service.
added as requirement 5.11.2
71) (CLOSED) Changed text "5.6.8: Ability to constrain load on 71) (CLOSED) Changed text "5.6.8: Ability to constrain load on
devices" to devices" to
The NSIS architecture should give the ability to constrain the load The NSIS architecture should give the ability to constrain the load
(CPU load, memory space, signaling bandwidth consumption and (CPU load, memory space, signaling bandwidth consumption and
signaling intensity) on devices where it is needed. This can be signaling intensity) on devices where it is needed. This can be
achieved by many different methods. Examples, and this are only achieved by many different methods. Examples, and this are only
Brunner, et al. Informational [Page 50]
Requirements for QoS Signaling Protocols May 2002
examples, include message aggregation, by ignoring signaling examples, include message aggregation, by ignoring signaling
message, header compression, or minimizing functionality. The message, header compression, or minimizing functionality. The
framework may choose any method as long as the requirement is met. framework may choose any method as long as the requirement is met.
72) (OPEN) request to add "Error notification and error location" --------------------------
starting from -03 version
--------------------------
"An NSIS signaling node rejecting or releasing a reservation must 73) (CLOSED) add table of contents
indicate its identity. NSIS signalling should indicate why a Requirements for QoS Signaling Protocols July 2002
requested resource is not or no longer available. "
Compared to 5.3.4 this is about problems on the control plane
------------------------------------------------------ ------------------------------------------------------
Change Log Version 01 -> 02 Change Log Version 01 -> 02
- added issues 62-72 - added issues 62-72
- added some discussion text to open issues - added some discussion text to open issues
- req " highest possible network utilization" added (issue 33, - req " highest possible network utilization" added (issue 33,
closed) closed)
- issues closed: 34 (UMTS scenarios), 35 (PSTN gatway scenarios), - issues closed: 34 (UMTS scenarios), 35 (PSTN gatway scenarios),
skipping to change at line 2854 skipping to change at page 57, line 46
administrative domain. administrative domain.
- closed issue 57: add text about "Minimal impact on interior (core) - closed issue 57: add text about "Minimal impact on interior (core)
nodes" to requirement 5.6.8 "Ability to constrain load on devices" nodes" to requirement 5.6.8 "Ability to constrain load on devices"
- added requirement "Allow efficient QoS re-establishment after - added requirement "Allow efficient QoS re-establishment after
handover", closed issue 60. handover", closed issue 60.
- changed text in 5.3.2 - changed text in 5.3.2
Brunner, et al. Informational [Page 51] ------------------------------------------------------
Change Log Version 02 -> 03 ([X] specify the open issue above)
[1] Scenarios add/change/remove (e.g. VPN).
Question: scenarios covering signalling for things other than QoS?
Georgios/Lars will provide justification & if successful Marcus will
add it. (done)
[7] Handoff decision and trigger sources (in or out of scope).
Agreed: NSIS is not going to solve this problem, has to interact
with protocols that do. Add text to exclusions section. (done)
Requirements for QoS Signaling Protocols July 2002
[8] NSIS should allow bidirectional reservations as an optimisation
where the network topology allows it. (done)
[14] Grouping of microflows. Added (as a MAY, probably). Network
does not need to know relationship exists. Add justification of why
this is an optimization. (done)
[16] Closed. (done)
[26] Interaction with seamoby. Add requirement to say that we are
interworking in the area of mobility protocols (e.g. CT and CAR
discovery). (done)
[28] Asynchronous events from the network. REH & Sven to propose
wording including some motivation as examples. Issues to do with
locality and scenarios. (resilience draft from Sven)
[29] NSIS in case of handovers. No change needed concerning
handovers. (closed the issue: done)
[37] Ownership of a reservation. Close issue and handle it within
security section. (done, changed security req text)
[39] Simplify security section. (done)
[40] Mobility requirements - don't add. Closed. (done)
[42] Add assumption that QoS monitoring is application/service
specific and out of scope. (done)
[43] Notification of QI/QC/QR. Closed earlier. (done, put together
with issue 28)
[44] Resource availability query. Query not as 'real' reservation
is part of service definition. May need new requirement about
endpoint controlling locality of signalling.
[45] Automatic re-installation. Removed, leave open option to supply
text for new requirement. (done)
[46] Scenarios for failure and recovery cases. Remove, invite
individual contributions. (done)
[47] Traffic engineering and route pinning issues. Assumption: NSIS
should work with networks using standard L3 routing. NSIS should not
be broken by networks which do non-traditional L3 routing. (done)
[52] Closed. Aspect of AAA (authentication --> authorisation)
solution or service definition. (done)
[53] Sven et al. to write submissions.
[59] Covered under [53].
[61] Closed. (done)
[64] Closed (no new text except maybe motherhood statements). (done)
Requirements for QoS Signaling Protocols July 2002
[65] Considered [53].
[66] Closed (not included elsewhere).(done)
[67] Closed (already covered). (done)
[68] Merge with 5.3.2 to reflect wanting to avoid stale state
(somehow). (done)
[69] Closed (already covered in transport service quality
requirement). Protocol design must take into account reliability
concerns. (done)
[70] Add something about graceful failover to general protocol
requirements section. (done)
[72] Closed. Should be possible for NSIS to transport useful error
messages.
- changed security text
- rearranged open issues (open ones on top)
 End of changes. 

This html diff was produced by rfcdiff 1.23, available from http://www.levkowetz.com/ietf/tools/rfcdiff/