draft-ietf-ccamp-oam-configuration-fwk-02.txt   draft-ietf-ccamp-oam-configuration-fwk-03.txt 
Network Working Group A. Takacs Network Working Group A. Takacs
Internet-Draft Ericsson Internet-Draft Ericsson
Intended status: Standards Track D. Fedyk Intended status: Standards Track D. Fedyk
Expires: April 29, 2010 Alcatel-Lucent Expires: August 1, 2010 Alcatel-Lucent
J. He J. He
Huawei Huawei
October 26, 2009 January 28, 2010
OAM Configuration Framework and Requirements for GMPLS RSVP-TE OAM Configuration Framework and Requirements for GMPLS RSVP-TE
draft-ietf-ccamp-oam-configuration-fwk-02 draft-ietf-ccamp-oam-configuration-fwk-03
Abstract
OAM is an integral part of transport connections, hence it is
required that OAM functions are activated/deactivated in sync with
connection commissioning/decommissioning; avoiding spurious alarms
and ensuring consistent operation. In certain technologies OAM
entities are inherently established once the connection is set up,
while other technologies require extra configuration to establish and
configure OAM entities. This document specifies extensions to
RSVP-TE to support the establishment and configuration of OAM
entities along with LSP signaling.
Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in
Status of this Memo Status of this Memo
This Internet-Draft is submitted to IETF in full conformance with the This Internet-Draft is submitted to IETF in full conformance with the
provisions of BCP 78 and BCP 79. provisions of BCP 78 and BCP 79.
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.
skipping to change at page 1, line 35 skipping to change at page 2, line 32
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." 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.
This Internet-Draft will expire on April 29, 2010. This Internet-Draft will expire on August 1, 2010.
Copyright Notice Copyright Notice
Copyright (c) 2009 IETF Trust and the persons identified as the Copyright (c) 2010 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents in effect on the date of Provisions Relating to IETF Documents
publication of this document (http://trustee.ietf.org/license-info). (http://trustee.ietf.org/license-info) in effect on the date of
Please review these documents carefully, as they describe your rights publication of this document. Please review these documents
and restrictions with respect to this document. carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
Abstract include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
OAM is an integral part of transport connections, hence it is described in the BSD License.
required that OAM functions are activated/deactivated in sync with
connection commissioning/decommissioning; avoiding spurious alarms
and ensuring consistent operation. In certain technologies OAM
entities are inherently established once the connection is set up,
while other technologies require extra configuration to establish and
configure OAM entities. This document specifies extensions to
RSVP-TE to support the establishment and configuration of OAM
entities along with LSP signaling.
Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4
2. Requirements . . . . . . . . . . . . . . . . . . . . . . . . . 6 2. Requirements . . . . . . . . . . . . . . . . . . . . . . . . . 6
3. GMPLS RSVP-TE Extensions . . . . . . . . . . . . . . . . . . . 9 3. GMPLS based OAM Configuration . . . . . . . . . . . . . . . . 8
3.1. Operation overview . . . . . . . . . . . . . . . . . . . . 9 3.1. Establishment of OAM Entities and Functions . . . . . . . 8
3.2. LSP Attributes flags . . . . . . . . . . . . . . . . . . . 10 3.2. Adjustment of OAM Parameters . . . . . . . . . . . . . . . 10
3.3. OAM Configuration TLV . . . . . . . . . . . . . . . . . . 11 3.3. Deleting OAM Entities . . . . . . . . . . . . . . . . . . 10
3.4. TCME Configuration TLV . . . . . . . . . . . . . . . . . . 13 4. RSVP-TE Extensions . . . . . . . . . . . . . . . . . . . . . . 12
3.5. NIME Configuration TLV . . . . . . . . . . . . . . . . . . 14 4.1. LSP Attributes Flags . . . . . . . . . . . . . . . . . . . 12
3.6. Monitoring Disabled - Admin_Status bit . . . . . . . . . . 15 4.2. OAM Configuration TLV . . . . . . . . . . . . . . . . . . 12
3.7. OAM configuration errors . . . . . . . . . . . . . . . . . 15 4.2.1. OAM Function Flags Sub-TLV . . . . . . . . . . . . . . 14
4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 17 4.2.2. Technology Specific sub-TLVs . . . . . . . . . . . . . 14
5. Security Considerations . . . . . . . . . . . . . . . . . . . 18 4.3. Administrative Status Information . . . . . . . . . . . . 14
6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 19 4.4. Handling OAM Configuration Errors . . . . . . . . . . . . 15
Appendix A. Discussion on alternatives . . . . . . . . . . . . . 20 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 16
7. References . . . . . . . . . . . . . . . . . . . . . . . . . . 22 6. Security Considerations . . . . . . . . . . . . . . . . . . . 17
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 24 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 18
Appendix A. Discussion on Alternatives . . . . . . . . . . . . . 19
8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 22
1. Introduction 1. Introduction
GMPLS is designed as an out-of-band control plane supporting dynamic GMPLS is designed as an out-of-band control plane supporting dynamic
connection provisioning for any suitable data plane technology; connection provisioning for any suitable data plane technology;
including spatial switching (e.g., incoming port or fiber to outgoing including spatial switching (e.g., incoming port or fiber to outgoing
port or fiber), wavelength-division multiplexing (e.g., DWDM), time- port or fiber), wavelength-division multiplexing (e.g., DWDM), time-
division multiplexing (e.g., SONET/SDH, G.709), and lately Ethernet division multiplexing (e.g., SONET/SDH, G.709), and lately Ethernet
Provider Backbone Bridging -- Traffic Engineering (PBB-TE) and MPLS Provider Backbone Bridging -- Traffic Engineering (PBB-TE) and MPLS
Transport Profile (MPLS-TP). In most of these technologies there are Transport Profile (MPLS-TP). In most of these technologies there are
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selectively configurable. selectively configurable.
In general, it is required that the management plane and control In general, it is required that the management plane and control
plane connection establishment mechanisms are synchronized with OAM plane connection establishment mechanisms are synchronized with OAM
establishment and activation. In particular, if the GMPLS control establishment and activation. In particular, if the GMPLS control
plane is employed it is desirable to bind OAM setup and configuration plane is employed it is desirable to bind OAM setup and configuration
to connection establishment signaling to avoid two separate to connection establishment signaling to avoid two separate
management/configuration steps (connection setup followed by OAM management/configuration steps (connection setup followed by OAM
configuration) which increases delay, processing and more importantly configuration) which increases delay, processing and more importantly
may be prune to misconfiguration errors. Once OAM entities are setup may be prune to misconfiguration errors. Once OAM entities are setup
and configured pro-active as well as on-demand OAM functions can be and configured, pro-active as well as on-demand OAM functions can be
activated via the management plane. On the other hand, it should be activated via the management plane. On the other hand, it should be
possible to activate/deactivate pro-active OAM functions via the possible to activate/deactivate pro-active OAM functions via the
GMPLS control plane as well. GMPLS control plane as well.
This document describes requirements on OAM configuration and control This document describes requirements on OAM configuration and control
via RSVP-TE, and specifies extensions to the RSVP-TE protocol via RSVP-TE, and specifies extensions to the RSVP-TE protocol
providing a framework to configure and control OAM entities along providing a framework to configure and control OAM entities along
with capability to carry technology specific information. Extensions with the capability to carry technology specific information.
can be grouped into generic elements that are applicable to any OAM Extensions can be grouped into generic elements that are applicable
solution and technology specific elements that provide additional to any OAM solution and technology specific elements that provide
configuration parameters only needed for a specific OAM technology. additional configuration parameters, only needed for a specific OAM
This document specifies the technology agnostic elements which alone technology. This document specifies the technology agnostic
can be used to establish and control OAM entities in the case no elements, which alone can be used to establish and control OAM
technology specific information is needed, and specifies the way entities in the case no technology specific information is needed,
additional technology specific OAM parameters are provided. and specifies the way additional technology specific OAM parameters
are provided.
This document addresses end-to-end OAM configuration, that is, the
setup of OAM entities bound to an end-to-end LSP, and configuration
and control of OAM functions running end-to-end in the LSP.
Configuration of OAM entities for LSP segments and tandem connections
are out of the scope of this document.
The mechanisms described in this document provide an additional The mechanisms described in this document provide an additional
option for bootstrapping OAM that is not intended to replace or option for bootstrapping OAM that is not intended to replace or
deprecate the use of other technology specific OAM bootstrapping deprecate the use of other technology specific OAM bootstrapping
techniques; e.g., LSP Ping [RFC4379] for MPLS networks. The techniques; e.g., LSP Ping [RFC4379] for MPLS networks. The
procedures specified in this document are intended only for use in procedures specified in this document are intended only for use in
environments where RSVP-TE signaling is already in use to set up the environments where RSVP-TE signaling is already in use to set up the
LSPs that are to be monitored using OAM. LSPs that are to be monitored using OAM.
2. Requirements 2. Requirements
MPLS OAM requirements are described in [RFC4377]. It provides MPLS OAM requirements are described in [RFC4377], which provides
requirements to create consistent OAM functionality for MPLS requirements to create consistent OAM functionality for MPLS
networks. GMPLS OAM requirements are described in [GMPLS-OAM]. The networks.
GMPLS OAM requirements are based on the MPLS OAM requirements
[RFC4377], in addition it also considers the existing OAM techniques
in non-packet networks.
The following list is an excerpt of MPLS OAM requirements documented The following list is an excerpt of MPLS OAM requirements documented
in [RFC4377]. Only a few requirements are discussed that bear a in [RFC4377]. Only a few requirements are discussed that bear a
direct relevance to the discussion set forth in this document. direct relevance to the discussion set forth in this document.
o It is desired to support the automation of LSP defect detection. o It is desired to support the automation of LSP defect detection.
It is especially important in cases where large numbers of LSPs It is especially important in cases where large numbers of LSPs
might be tested. might be tested.
o In particular some LSPs may require automated ingress-LSR to o In particular some LSPs may require automated ingress-LSR to
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synchronizing defect detection times by setting appropriately synchronizing defect detection times by setting appropriately
bounded detection timeframes. bounded detection timeframes.
MPLS-TP defines a profile of MPLS targeted at transport applications MPLS-TP defines a profile of MPLS targeted at transport applications
[MPLS-TP-FWK]. This profile specifies the specific MPLS [MPLS-TP-FWK]. This profile specifies the specific MPLS
characteristics and extensions required to meet transport characteristics and extensions required to meet transport
requirements, including providing additional OAM, survivability and requirements, including providing additional OAM, survivability and
other maintenance functions not currently supported by MPLS. other maintenance functions not currently supported by MPLS.
Specific OAM requirements for MPLS-TP are specified in Specific OAM requirements for MPLS-TP are specified in
[MPLS-TP-OAM-REQ]. MPLS-TP poses requirements on the control plane [MPLS-TP-OAM-REQ]. MPLS-TP poses requirements on the control plane
to configure and control OAM entities. to configure and control OAM entities:
o The use of OAM functions SHOULD be optional for the operator. A o The use of OAM functions SHOULD be optional for the operator. A
network operator SHOULD be able to choose which OAM functions to network operator SHOULD be able to choose which OAM functions to
use and which Maintenance Entity to apply them to. use and which Maintenance Entity to apply them to.
o The MPLS-TP control plane MUST support the configuration and o The MPLS-TP control plane MUST support the configuration and
modification of OAM maintenance points as well as the activation/ modification of OAM maintenance points as well as the activation/
deactivation of OAM when the transport path is established or deactivation of OAM when the transport path is established or
modified. OAM functions SHOULD be configurable as part of modified. OAM functions SHOULD be configurable as part of
connectivity (LSP or PW) management. connectivity (LSP or PW) management.
Ethernet Connectivity Fault Management (CFM) defines an adjunct
connectivity monitoring OAM flow to check the liveliness of Ethernet
networks [IEEE-CFM]. With PBB-TE [IEEE-PBBTE] Ethernet networks will
support explicitly-routed Ethernet connections. CFM can be used to
track the liveliness of PBB-TE connections and detect data plane
failures. In IETF the GMPLS controlled Ethernet Label Switching
(GELS) [GELS-Framework] work is extending the GMPLS control plane to
support the establishment of point-to-point PBB-TE data plane
connections. Without control plane support separate management
commands would be needed to configure and start CFM.
GMPLS based OAM configuration and control should be general to be GMPLS based OAM configuration and control should be general to be
applicable to a wide range of data plane technologies and OAM applicable to a wide range of data plane technologies and OAM
solution. There are three typical data plane technologies used for solutions. There are three typical data plane technologies used for
transport application, which are wavelength based such as WSON, TDM transport application, which are wavelength based such as WSON, TDM
based such as SDH/SONET, packet based such as MPLS-TP [MPLS-TP-FWK] based such as SDH/SONET, packet based such as MPLS-TP [MPLS-TP-FWK]
and Ethernet PBB-TE [IEEE-PBBTE]. In all these data planes, the and Ethernet PBB-TE [IEEE-PBBTE]. In all these data planes, the
operator MUST be able to configure and control the following OAM operator MUST be able to configure and control the following OAM
functions. functions.
o It MUST be possible to explicitly request the setup of OAM o It MUST be possible to explicitly request the setup of OAM
entities for the signaled LSP and provide specific information for entities for the signaled LSP and provide specific information for
the setup if this is required by the technology. the setup if this is required by the technology.
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to be able to balance the trade-off in fast failure detection and to be able to balance the trade-off in fast failure detection and
overhead it is beneficial to configure the frequency of continuity overhead it is beneficial to configure the frequency of continuity
check messages on a per LSP basis. check messages on a per LSP basis.
o Pro-active Performance Monitoring (PM) functions are continuously o Pro-active Performance Monitoring (PM) functions are continuously
collecting information about specific characteristics of the collecting information about specific characteristics of the
connection. For consistent measurement of Service Level connection. For consistent measurement of Service Level
Agreements (SLAs) it may be required that measurement points agree Agreements (SLAs) it may be required that measurement points agree
on a common probing rate to avoid measurement problems. on a common probing rate to avoid measurement problems.
o The extensions must allow the operator to use only a minimal set o The extensions MUST allow the operator to use only a minimal set
of OAM configuration and control features if the data plane of OAM configuration and control features if the data plane
technology, the OAM solution or network management policy allows. technology, the OAM solution or network management policy allows.
The extensions must be reusable as much as reasonably possible. The extensions must be reusable as much as reasonably possible.
That is generic OAM parameters and data plane or OAM technology That is generic OAM parameters and data plane or OAM technology
specific parameters must be separated. specific parameters must be separated.
3. GMPLS RSVP-TE Extensions 3. GMPLS based OAM Configuration
3.1. Operation overview
In general, two types of Maintenance Poits (MPs) can be In general, two types of Maintenance Poits (MPs) can be
distinguished: Maintenance End Points (MEPs) and Maintenance distinguished: Maintenance End Points (MEPs) and Maintenance
Intermediate Points (MIPs). MEPs are capable of initiating and Intermediate Points (MIPs). MEPs reside at the ends of an LSP and
terminating OAM messages for Fault Management (FM) and Performance are capable of initiating and terminating OAM messages for Fault
Monitoring (PM). MIPs on the other hand are located at transit nodes Management (FM) and Performance Monitoring (PM). MIPs on the other
of an LSP and are capable of reacting to some OAM messages but hand are located at transit nodes of an LSP and are capable of
otherwise do not initiate messages. Maintenance Entity (ME) refers reacting to some OAM messages but otherwise do not initiate messages.
to an association of MEPs and MIPs that are provisioned to monitor an Maintenance Entity (ME) refers to an association of MEPs and MIPs
LSP. The ME association is achieved by configuring MPs of an ME with that are provisioned to monitor an LSP. The ME association is
the same unique ME Assocication ID (MA ID). Each MEP must have achieved by configuring MPs to belong to the same ME.
unique identification (MEP ID) within a Maintenance Entity.
When an LSP is signaled forwarding association is established between
endpoints and transit nodes via label bindings. This association
creates a context for the OAM entities monitoring the LSP. On top of
this association OAM entities may be configured with an MA ID and MEP
IDs. The MA ID may be used to detect misconfiguration errors and
leaking OAM traffic. While the MEP ID can be used to demultiplex and
identify the originating MEP of OAM messages. Since MIPs do not
originate OAM packets, on top of the configuration of Maintenance
Entity associations, no specific configuration is required for them.
Along the LSP several Tandem Connections may be provisioned and
associated to the end-to-end connection. These Tandem Connections
may implement their own OAM monitoring entities. The Tandem
Connection Maintenance Entities (TCMEs) provide the same monitoring
capabilities for a segment of a connection as what is possible on an
end-to-end basis. As the endpoints of a TCME may be (and usually
are) intermediate nodes of an end-to-end LSP, the placement of TCME
ingress and egress endpoints must be explicitly identified.
Altough provisioned together with the end-to-end connection, each
TCME defines a new context for the OAM entities, which is independent
from the end-to-end connection. The MA ID and MEP IDs for a TCME are
within this new context.
When an LSP is signaled Non-Intrusive Maintenance Elements (NIME) may When an LSP is signaled, forwarding association is established
be deployed along the path. These elements differ from the MIPs as between endpoints and transit nodes via label bindings. This
they implemetn egress MEP functions: they not only process OAM association creates a context for the OAM entities monitoring the
messages but they can also trigger consequent actions, for instance, LSP. On top of this association OAM entities may be configured to
initiate segment protection switching. The NIMEs belong to the OAM unambigously identify MPs and MEs.
entity context of the end-to-end LSP and, thus, the same MA ID is
applied. As the NIMEs are placed at intermediate nodes, their
placement must be explicitly indicated.
In addition to the MA and MEP identification parameters pro-active In addition to MP and ME identification parameters pro-active OAM
OAM functions (e.g., Continuity Check (CC), Performance Monitoring) functions (e.g., Continuity Check (CC), Performance Monitoring) may
may have specific parameters requiring configuration as well. In have specific parameters requiring configuration as well. In
particular, the frequency of periodic CC packets and the measurement particular, the frequency of periodic CC packets and the measurement
interval for loss and delay measurements may need to be configured. interval for loss and delay measurements may need to be configured.
MEP
+-------------+
|OAM Functions|
| FM | PM |
+------+------+
| MEP ID |
+-------------+
| MA ID |
+-------------+
+-------------+
| connection |
+-------------+
In some cases all the above parameters may be either derived form In some cases all the above parameters may be either derived form
some exiting information or pre-configured default values can be some exiting information or pre-configured default values can be
used. In the simplest case the control plane needs to provide used. In the simplest case the control plane needs to provide
information whether or not a MA with MPs need to be setup for the information whether or not OAM entities need to be setup for the
signaled LSP. If OAM entities are created signaling must provide signaled LSP. If OAM entities are created signaling must provide
means to activate/deactivate OAM message flows and associated alarms. means to activate/deactivate OAM message flows and associated alarms.
MA and MEP IDs as well as configuration of OAM functions are OAM identifiers as well as the configuration of OAM functions are
technology specific, i.e., vary depending on the data plane technology specific, i.e., vary depending on the data plane
technology and the chosen OAM solution. In addition, for any given technology and the chosen OAM solution. In addition, for any given
data plane technology a set of OAM solutions may be applicable. The data plane technology a set of OAM solutions may be applicable. The
OAM configuration framework allows selecting a specific OAM solution OAM configuration framework allows selecting a specific OAM solution
to be used for the signaled LSP and provides technology specific TLVs to be used for the signaled LSP and provides technology specific TLVs
to carry further detailed configuration information. to carry further detailed configuration information.
3.2. LSP Attributes flags 3.1. Establishment of OAM Entities and Functions
In order to avoid spurious alarms OAM functions must be setup and
enabled in the appropriate order. When using the GMPLS control
plane, establishment and enabling of OAM functions must be bound to
RSVP-TE message exchanges.
An LSP may be signaled and established without OAM configuration
first, and OAM entities may be added later with a subsequent re-
signaling of the LSP. Alternatively, the LSP may be setup with OAM
entities right with the first signaling of the LSP. The below
procedures apply to both cases.
Before the initiator first sends a Path messages with OAM
Configuration information, it MUST establish and configure the
corresponding OAM entities locally, however OAM source functions MUST
NOT start sending any OAM messages. In the case of bidirectional
connections, the initiator node MUST setup the OAM sink function to
be prepared to receive OAM messages but MUST suppress any OAM alarms
(e.g., due to missing or unidentified OAM messages). The Path
message MUST be sent with the "OAM Alarms Enabled" ADMIN_STATUS flag
cleared, i.e, data plane OAM alarms are suppressed.
When the Path message arrives at the receiver, the remote end MUST
establish and configure OAM entities according to the OAM information
provided in Path message. If this is not possible a PathErr SHOULD
be sent and neither the OAM entities nor the LSP SHOULD be
established. If OAM entities are established successfully, the OAM
sink function MUST be prepared to receive OAM messages but MUST not
generate any OAM alarms (e.g., due to missing or unidentified OAM
messages). In the case of bidirectional connections, an OAM source
function MUST be setup and, according to the requested configuration,
it MUST start sending OAM messages. Then a Resv message is sent
back, including the OAM Configuration TLV that corresponds to the
actually established and configured OAM entities and functions.
Depending on the OAM technology, some elements of the OAM
Configuration TLV MAY be updated/changed; i.e., if the remote end is
not supporting a certain OAM configuration it may suggest an
alternative setting, which may or may not be accepted by the
initiator of the Path message. If it is accepted, the initiator will
reconfigure its OAM functions according to the information received
in the Resv message. If the alternate setting is not acceptable a
ResvErr may be sent tearing down the LSP. Details of this operation
are technology specific and should be described in accompanying
technology specific documents.
When the initiating side receives the Resv message it completes any
pending OAM configuration and enables the OAM source function to send
OAM messages.
After this round, OAM entities are established and configured for the
LSP and OAM messages MAY already be exchanged. OAM alarms can now be
enabled. The initiator, while still keeping OAM alarms disabled
sends a Path message with "OAM Alarms Enabled" ADMIN_STATUS flag set.
The receiving node enables the OAM alarms after processing the Path
message. The initiator enables OAM alarms after it receives the Resv
message. Data plane OAM is now fully functional.
3.2. Adjustment of OAM Parameters
There may be a need to change the parameters of an already
established and configured OAM function during the lifetime of the
LSP. To do so the LSP needs to be re-signaled with the updated
parameters. OAM parameters influence the content and timing of OAM
messages and identify the way OAM defects and alarms are derived and
generated. Hence, to avoid spurious alarms, it is important that
both sides, OAM sink and source, are updated in a synchronized way.
First, the alarms of the OAM sink function should be suppressed and
only then should expected OAM parameters be adjusted. Subsequently,
the parameters of the OAM source function can be updated. Finally,
the alarms of the OAM sink side can be enabled again.
In accordance with the above operation, the LSP MUST first be re-
signaled with "OAM Alarms Enabled" ADMIN_STATUS flag cleared and
including the updated OAM Configuration TLV corresponding to the new
parameter settings. The initiator MUST keep its OAM sink and source
functions running unmodified, but it MUST suppress OAM alarms after
the updated Path message is sent. The receiver MUST first disable
all OAM alarms, then update the OAM paramaters according to the
information in the Path message and reply with a Resv message
acknowledging the changes by including the OAM Configuration TLV.
Note that the receiving side has the possibility to adjust the
requested OAM configuration parameters and reply with and updated OAM
Configuration TLV in the Resv message, reflecting the actually
configured values. However, in order to avoid an extensive
negotiation phase, in the case of adjusting already configured OAM
functions, the receiving side SHOULD NOT update the parameters
requested in the Path message to an extent that would provide lower
performance than what has been configured previously.
The initiator MUST only update its OAM sink and source functions
after it received the Resv message. After this Path/Resv message
exchange (in both unidirectional and bidirectional LSP cases) the OAM
parameters are updated and OAM is running according the new parameter
settings. However OAM alarms are still disabled. A subsequent Path/
Resv message exchange with "OAM Alarms Enabled" ADMIN_STATUS flag set
is needed to enable OAM alarms again.
3.3. Deleting OAM Entities
In some cases it may be useful to remove some or all OAM entities and
functions from an LSP without actually tearing down the connection.
To avoid any spurious alarm, first the LSP SHOULD be re-signaled with
"OAM Alarms" ADMIN_STATUS flag cleared but unchanged OAM
configuration. Subsequently, the LSP is re-signaled with "OAM MEP
Entities desired" and "OAM MIP Entities desired" LSP ATTRIBUTES flags
cleared, and without the OAM Configuration TLV, this MUST result in
the deletion of all OAM entities associated with the LSP. All
control and data plane resources in use by the OAM entities and
functions SHOULD be freed up. Alternatively, if only some OAM
functions need to be removed, the LSP is re-signalled with the
updated OAM Configuration TLV. Changes between the contents of the
previously signalled OAM Configuration TLV and the currently received
TLV represent which functions SHOULD be removed/added.
First, OAM source functions SHOULD be deleted and only after that
SHOULD the associated OAM sink functions be removed, this will ensure
that OAM messages do not leak outside the LSP. To this end the
initiator, before sending the Path message, SHOULD remove the OAM
source, hence terminating the OAM message flow associated to the
downstream direction. In the case of a bidirectional connection, it
SHOULD leave in place the OAM sink functions associated to the
upstream direction. The remote end, after receiving the Path
message, SHOULD remove all associated OAM entities and functions and
reply with a Resv message without an OAM Configuration TLV. The
initiator completely removes OAM entities and functions after the
Resv message arrived.
4. RSVP-TE Extensions
4.1. LSP Attributes Flags
In RSVP-TE the Flags field of the SESSION_ATTRIBUTE object is used to In RSVP-TE the Flags field of the SESSION_ATTRIBUTE object is used to
indicate options and attributes of the LSP. The Flags field has 8 indicate options and attributes of the LSP. The Flags field has 8
bits and hence is limited to differentiate only 8 options. [RFC4420] bits and hence is limited to differentiate only 8 options. [RFC5420]
defines new objects for RSVP-TE messages to allow the signaling of defines new objects for RSVP-TE messages to allow the signaling of
arbitrary attribute parameters making RSVP-TE easily extensible to arbitrary attribute parameters making RSVP-TE easily extensible to
support new applications. Furthermore, [RFC4420] allows options and support new applications. Furthermore, [RFC5420] allows options and
attributes that do not need to be acted on by all Label Switched attributes that do not need to be acted on by all Label Switched
Routers (LSRs) along the path of the LSP. In particular, these Routers (LSRs) along the path of the LSP. In particular, these
options and attributes may apply only to key LSRs on the path such as options and attributes may apply only to key LSRs on the path such as
the ingress LSR and egress LSR. Options and attributes can be the ingress LSR and egress LSR. Options and attributes can be
signaled transparently, and only examined at those points that need signaled transparently, and only examined at those points that need
to act on them. The LSP_ATTRIBUTES and the LSP_REQUIRED_ATTRIBUTES to act on them. The LSP_ATTRIBUTES and the LSP_REQUIRED_ATTRIBUTES
objects are defined in [RFC4420] to provide means to signal LSP objects are defined in [RFC5420] to provide means to signal LSP
attributes and options in the form of TLVs. Options and attributes attributes and options in the form of TLVs. Options and attributes
signaled in the LSP_ATTRIBUTES object can be passed transparently signaled in the LSP_ATTRIBUTES object can be passed transparently
through LSRs not supporting a particular option or attribute, while through LSRs not supporting a particular option or attribute, while
the contents of the LSP_REQUIRED_ATTRIBUTES object must be examined the contents of the LSP_REQUIRED_ATTRIBUTES object must be examined
and processed by each LSR. One TLV is defined in [RFC4420]: the and processed by each LSR. One TLV is defined in [RFC5420]: the
Attributes Flags TLV. Attributes Flags TLV.
One bit (10 IANA to assign): "OAM MEP entities desired" is allocated One bit (10 IANA to assign): "OAM MEP entities desired" is allocated
in the LSP Attributes Flags TLV. If the "OAM MEP entities desired" in the LSP Attributes Flags TLV. If the "OAM MEP entities desired"
bit is set it is indicating that the establishment of OAM MEP bit is set it is indicating that the establishment of OAM MEP
entities are required at the endpoints of the signaled LSP. If the entities are required at the endpoints of the signaled LSP. If the
establishment of MEPs is not supported an error must be generated: establishment of MEPs is not supported an error must be generated:
"OAM Problem/MEP establishment not supported". "OAM Problem/MEP establishment not supported".
If the "OAM MEP entities desired" bit is set and additional If the "OAM MEP entities desired" bit is set and additional
parameters are needed to configure the OAM entities an OAM parameters are needed to be configured the OAM entities an OAM
Configuration TLV may be included in the LSP_ATTRIBUTES object. Configuration TLV may be included in the LSP_ATTRIBUTES object.
One bit (11 IANA to assign): "OAM MIP entities desired" is allocated One bit (11 IANA to assign): "OAM MIP entities desired" is allocated
in the LSP Attributes Flags TLV. If the "OAM MIP entities desired" in the LSP Attributes Flags TLV. This bit can only be set if the
bit is set it is indicating that the establishment of OAM MIP "OAM MEP entities desired" bit is set. If the "OAM MIP entities
entities are required at the transit nodes of the signaled LSP. This desired" bit is set in the LSP_ATTRIBUTES Flags TLV, it is indicating
bit can only be set if the "OAM MEP entities desired" bit is set. If that the establishment of OAM MIP entities is required at every
the establishment of MIPs is not supported an error must be transit node of the signalled LSP. If the establishment of a MIP is
generated: "OAM Problem/MIP establishment not supported". not supported an error must be generated: "OAM Problem/MIP
establishment not supported".
One bit (12 IANA to assign): "Alarm indication desired" is allocated
in the LSP Attributes Flags TLV. If the "Alarm indication desired"
bit is set it is indicating that the OAM entities of the signaled LSP
should be notified of lower layer failures. In the case of
hierarchical LSPs this will create an association between the
underlying (server) LSP's OAM entities and the currently signaled
(client) LSP's OAM entities.
3.3. OAM Configuration TLV 4.2. OAM Configuration TLV
This TLV specifies which OAM technology/method should be used for the This TLV provides information about which OAM technology/method
LSP. The OAM Configuration TLV is carried in the LSP_ATTRIBUTES should be used and carries sub-TLVs for any additional OAM
object in Path messages. configuration information. The OAM Configuration TLV may be carried
in the LSP_ATTRIBUTES or LSP_REQUIRED_ATTRIBUTES object in Path and
Resv messages.
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type (2) (IANA) | Length | | Type (2) (IANA) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OAM Type | Reserved | OAM Function | | OAM Type | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | | |
~ sub-TLVs ~ ~ sub-TLVs ~
| | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type: indicates a new type: the OAM Configuration TLV (2) (IANA to Type: indicates a new type: the OAM Configuration TLV (2) (IANA to
assign). assign).
OAM Type: specifies the technology specific OAM method. If the OAM Type: specifies the technology specific OAM method. If the
requested OAM method is not supported an error must be generated: requested OAM method is not supported an error must be generated:
"OAM Problem/Unsupported OAM Type". "OAM Problem/Unsupported OAM Type".
This document defines no types. The receiving node based on the OAM
Type will check if a corresponding technology specific OAM
configuration sub-TLV is included. If different technology specific
OAM configuration sub-TLV is included than what was specified in the
OAM Type an error must be generated: "OAM Problem/OAM Type Mismatch".
OAM Type Description OAM Type Description
------------ -------------------- ------------ --------------------
0-255 Reserved 0-255 Reserved
There is a hierarchy in between the OAM configuration elements. This document defines no types. IANA is requests to maintain the
First, the "OAM MEP (and MIP) entities desired" flag needs to be set, values in a new "RSVP-TE OAM Configuration Registry".
if it is set an "OAM Configuration TLV" may be included in the
LSP_ATTRIBUTES object, if this TLV is present based on the OAM Type a
technology specific OAM configuration sub-TLV may be present. If
this hierarchy is broken (e.g., "OAM MEP entities desired" flag is
not set but an OAM Configuration TLV is present an error must be
generated: "OAM Problem/Configuration Error".
OAM Function Flags: specifies pro-active OAM functions (e.g.,
connectivity monitoring, loss and delay measurement) that should be
established and configured. If the selected OAM Function(s) is(are)
not supported an error must be generated: "OAM Problem/Unsupported
OAM Function".
This document defines the following flags.
OAM Function Flag Description
--------------------- ---------------------------
0 Connectivity Monitoring
1 Performance Monitoring/Loss
2 Performance Monitoring/Delay
3.4. TCME Configuration TLV
Two TCME Configuration TLVs together specify a Tandem Connection
Monitoring entity: they designate the TCM ingress and TCM egress
MEPs, respectively. TCME Configuration TLVs are carried in
HOP_ATTRIBUTES subobjects [HOP_ATTR] in the ERO, the corresponding
node in the ERO identifies where TCME MEP is placed. Both TCME
Configuration TLVs of the same TCME must specify the same OAM
technology and method.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type (2) (IANA) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OAM Type |H|M| Level | OAM Functions |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SUB TLVs |
~ ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type: indicates a new type: the TCME Configuration TLV (2) (IANA to
assign).
OAM Type: specifies the technology specific OAM method. The OAM Type
values defined for OAM Configuration TLV are applied here. If the
requested OAM method is not supported an error must be generated:
"OAM Problem/Unsupported OAM Type".
One bit (Flag H) is allocated to indicate which endpoint of a TCME is
encoded by the TCME Configuration TLV. Setting this flag indicates
the ingress endpoints while clearing it indicates the egress one.
One bit (Flag M) "TCME MIP entities desired" is allocated. This flag
indicates if OAM MIP entities monitoring the TCME are required. If
this function is not supported an error must be generated: "OAM
Problem/TCME MIP establishment not supported".
Level provides a key for the ingress node to determine the egress of
the same TCME. Therefore, the same Level values must be set to the
ingress and egress endpoints of the same TCME. Overlapping
(including nesting) TCM entities must use different Level values, but
two entries not having common segments may use the same Level value.
Value 0 is reserved and must not be used to identify a TCM entity.
Futher technology specific constraints of the Level value may be
defined by accompying documents.
OAM Function Flags: specifies pro-active OAM functions (e.g.,
connectivity monitoring, loss and delay measurement) that should be
established and configured. Same flags are applied as for OAM
Configuration TLV.
Both TLVs may contain technology sub-TLVs and the encoded sub-TLVs
are relevant to the referred monitoring endpoint. The TCM ingress
may update the OAM configuration of the egress point by changing
already defined sub-TLVs or by adding new sub-TLVs.
If the node, where TCME endpoint is to be configured, does not
support that feature, must generate an error: "OAM Problem/TCM not
supported".
Since a TCME Configuration TLV pair encodes a TCME, the ingress node The receiving node based on the OAM Type will check if a
must check if a proper TCME Configuration TLV encoding the egress MEP corresponding technology specific OAM configuration sub-TLV is
is included in the ERO. If no such TLV (i.e., the same Level value included. If the included technology specific OAM configuration sub-
is set and flag H is cleared) is found an error must be generated: TLV is different than what is specified in the OAM Type an error must
"OAM Problem/TCM Egress is not properly configured". be generated: "OAM Problem/OAM Type Mismatch".
The above check ensures that a TCM egress will not be configured Note that there is a hierarchical dependency in between the OAM
without peering TCM ingress. Therefore, there is no need TCME configuration elements. First, the "OAM MEP (and MIP) entities
ingress checking procedure at the TCME egress. desired" flag needs to be set. When it is set an "OAM Configuration
TLV" may be included in the LSP_ATTRIBUTES or LSP_REQUIRED_ATTRIBUTES
Object. When this TLV is present, based on the "OAM Type" field, it
may carry a technology specific OAM configuration sub-TLV. If this
hierarchy is broken (e.g., "OAM MEP entities desired" flag is not set
but an OAM Configuration TLV is present) an error must be generated:
"OAM Problem/Configuration Error".
3.5. NIME Configuration TLV 4.2.1. OAM Function Flags Sub-TLV
Inserting a NIME Configuration TLV into a HOP_ATTRIBUTES object As the first sub-TLV one "OAM Function Flags sub-TLV" MUST be always
[HOP_ATTR] indicates that a non-intrusive monitoring element is to be included in the "OAM Configuration TLV". "OAM Function Flags"
configured. Futhermore, it encodes what OAM technology and method specifies which pro-active OAM functions (e.g., connectivity
should be used at that entity. monitoring, loss and delay measurement) and which fault management
signals MUST be established and configured. If the selected OAM
Function(s) is(are) not supported, an error must be generated: "OAM
Problem/Unsupported OAM Function".
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type (3) (IANA) | Length | | Type (1) (IANA) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OAM Type |D|U| Level | OAM Functions |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SUB TLVs | | |
~ ~ ~ OAM Function Flags ~
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type: indicates a new type: the NIM OAM Configuration TLV (3) (IANA
to assign).
OAM Type: specifies the technology specify OAM method. If the This document defines the following flags.
requested OAM method is not supported an error must be generated:
"OAM Problem/Unsupported OAM Type". The same OAM type values to be
used as for OAM Configuration TLV.
Level value indicates which OAM flow of the connection is monitored: OAM Function Flag Description
the end-to-end OAM flow (Level = 0) or TCM entity associated to the --------------------- ---------------------------
connection (Level > 0). 0 Continuity Check (CC)
1 Connectivity Verification (CV)
2 Performance Monitoring/Loss (PM/Loss)
3 Performance Monitoring/Delay (PM/Delay)
Two bits (Flags D,U) indicates the direction of the monitored entity. 4.2.2. Technology Specific sub-TLVs
The downstream traffic is monitored if flag D is set, while setting
flag U means monitoring the upstream direction. Both directions are
monitored if both flags are set. When both flags are cleared or the
flag U is set but the LSP is not bidirectional an error must be
generated: "OAM Problem/Invalid NIM direction defined".
OAM Function Flags: specifies pro-active OAM functions (e.g., One technology specific sub-TLV SHOULD be defined for each "OAM
connectivity monitoring, loss and delay measurement) that should be Type". This sub-TLV MUST contain any further OAM configuration
established and configured. Same procedures and flags applied as for information for that specific "OAM Type". The technology specific
OAM Configuration TLV. sub-TLV may be carried within the OAM Configuration TLV.
3.6. Monitoring Disabled - Admin_Status bit 4.3. Administrative Status Information
Administrative Status Information is carried in the ADMIN_STATUS Administrative Status Information is carried in the ADMIN_STATUS
Object. The Administrative Status Information is described in Object. The Administrative Status Information is described in
[RFC3471], the ADMIN_STATUS Object is specified for RSVP-TE in [RFC3471], the ADMIN_STATUS Object is specified for RSVP-TE in
[RFC3473]. [RFC3473].
One bit is allocated for the administrative control of OAM Two bits are allocated for the administrative control of OAM
monitoring. In addition to the Reflect (R) bit, 7 bits are currently monitoring. In addition to the Reflect (R) bit, 7 bits are currently
occupied (assigned by IANA or temporarily blocked by work in progress occupied (assigned by IANA or temporarily blocked by work in progress
Internet drafts). As the 24th bit (IANA to assign) this draft Internet drafts). As the 24th and 25th bits (IANA to assign) this
introduces the Monitoring Disabled (M) bit. When this bit is set the draft introduces the "OAM Flows Enabled" (M) and "OAM Alarms Enabled"
monitoring and OAM triggered alarms of the LSP are disabled (e.g., no (O) bits. When the "OAM Flows Enabled" bit is set, OAM packets are
continuity check messages are sent, no AIS is generated). sent if it is cleared no OAM packets are emitted. When the "OAM
Alarms Enabled" bit is set OAM triggered alarms are enabled and
associated consequent actions are executed including the notification
of the management system. When this bit is cleared, alarms are
suppressed and no action is executed and the management system is not
notified.
3.7. OAM configuration errors 4.4. Handling OAM Configuration Errors
To handle OAM configuration errors a new Error Code (IANA to assign) To handle OAM configuration errors a new Error Code (IANA to assign)
"OAM Problem" is introduced. To refer to specific problems a set of "OAM Problem" is introduced. To refer to specific problems a set of
Error Values is defined. Error Values is defined.
If a node does not support the establishment of OAM MEP or MIP If a node does not support the establishment of OAM MEP or MIP
entities it must use the error value (IANA to assign): "MEP entities it must use the error value (IANA to assign): "MEP
establishment not supported" or "MIP establishment not supported" establishment not supported" or "MIP establishment not supported"
respectively in the PathErr message. respectively in the PathErr message.
If a node does not support a specific OAM technology/solution it must If a node does not support a specific OAM technology/solution it must
use the error value (IANA to assign): "Unsupported OAM Type" in the use the error value (IANA to assign): "Unsupported OAM Type" in the
PathErr message. PathErr message.
If a different technology specific OAM configuration TLV is included If a different technology specific OAM configuration TLV is included
than what was specified in the OAM Type an error must be generated than what was specified in the OAM Type an error must be generated
with error value:"OAM Type Mismatch" in the PathErr message. with error value: "OAM Type Mismatch" in the PathErr message.
There is a hierarchy in between the OAM configuration elements. If There is a hierarchy in between the OAM configuration elements. If
this hierarchy is broken an the error value: "OAM Problem/ this hierarchy is broken the error value: "Configuration Error" must
Configuration Error" must be used in the PathErr message. be used in the PathErr message.
If a node does not support a specific OAM Function it must use the If a node does not support a specific OAM Function it must use the
error value (IANA to assign): "Unsupported OAM Function" in the error value: "Unsupported OAM Function" in the PathErr message.
PathErr message.
If an intermediate node is configured as a TCM ingress node, but no
egress node for the same TCM entity is encoded in the ERO it must use
"OAM Problem/TCM Egress is not properly configured" error value in
the PathErr message
If the node, where TCME endpoint is to be configured, does not
support that feature, must generate an error: "OAM Problem/TCM not
supported".
If the technology does not support deploying MIPs monitoring a TCME
an error must be generated by the TCME ingress: "OAM Problem/TCME MIP
establishment not supported".
If an intermediate node is configured as a non-intrusive monitoring
node, but direction flags encode an invalid direction (both flags are
set to 0 or flag "U" is set in the case of an unidirectional LSP) the
node must issue a PathErr message with "OAM Problem/invalid NIM
direction defined".
4. IANA Considerations 5. IANA Considerations
One bit (Monitoring Disabled (M)) needs to be allocated in the Two bits ("OAM Alarms Enabled" (O) and "OAM Flows Enabled" (M)) needs
ADMIN_STATUS Object. to be allocated in the ADMIN_STATUS Object.
One bit ("OAM entities desired") needs to be allocated in the LSP Two bits ("OAM MEP entities desired" and "OAM MIP entities desired")
Attributes Flag Registry. needs to be allocated in the LSP Attributes Flags Registry.
This document specifies one new TLVs to be carried in the This document specifies one new TLV to be carried in the
LSP_ATTRIBUTES and LSP_REQUIRED_ATTRIBUTES objects in Path messages: LSP_ATTRIBUTES and LSP_REQUIRED_ATTRIBUTES objects in Path and Resv
OAM Configuration TLV. messages: OAM Configuration TLV.
One new Error Code: "OAM Problem" and three new values: "MEP One new Error Code: "OAM Problem" and a set of new values: "MEP
establishment not supported", "MIP establishment not supported", establishment not supported", "MIP establishment not supported",
"Unsupported OAM Type" and "Unsupported OAM Function" needs to be "Unsupported OAM Type", "Configuration Error" and "Unsupported OAM
assigned. Function" needs to be assigned.
5. Security Considerations The IANA is requested to open a new registry: "RSVP-TE OAM
Configuration Registry" that maintains the "OAM Type" code points and
the allocations of "OAM Function Flags" within the OAM Configuration
TLV.
6. Security Considerations
The signaling of OAM related parameters and the automatic The signaling of OAM related parameters and the automatic
establishment of OAM entities introduces additional security establishment of OAM entities introduces additional security
considerations to those discussed in [RFC3473]. In particular, a considerations to those discussed in [RFC3473]. In particular, a
network element could be overloaded, if an attacker would request network element could be overloaded, if an attacker would request
liveliness monitoring, with frequent periodic messages, for a high liveliness monitoring, with frequent periodic messages, for a high
number of LSPs, targeting a single network element. number of LSPs, targeting a single network element.
Security aspects will be covered in more detailed in subsequent Security aspects will be covered in more detailed in subsequent
versions of this document. versions of this document.
6. Acknowledgements 7. Acknowledgements
The authors would like to thank Francesco Fondelli, Adrian Farrel, The authors would like to thank Francesco Fondelli, Adrian Farrel,
Loa Andersson, Eric Gray and Dimitri Papadimitriou for their useful Loa Andersson, Eric Gray and Dimitri Papadimitriou for their useful
comments. comments.
Appendix A. Discussion on alternatives Appendix A. Discussion on Alternatives
This appendix summarizes the discussions after IETF-71 about the way This appendix summarizes the discussions after IETF-71 about the way
OAM configuration information should be carried in RSVP-TE. OAM configuration information should be carried in RSVP-TE.
The first question is how the requirement for OAM establishment is The first question is how the requirement for OAM establishment is
signaled and how the operation of OAM is controlled. There is a signaled and how the operation of OAM is controlled. There is a
straightforward way to achieve these using existing objects and straightforward way to achieve these using existing objects and
fields: fields:
o Use one or more OAM flags in the LSP Attributes Flag TLV within o Use one or more OAM flags in the LSP Attributes Flag TLV within
skipping to change at page 22, line 5 skipping to change at page 21, line 5
carry configuration information of data plane entities, thus a new carry configuration information of data plane entities, thus a new
object like an "OAM_SPEC" may be a better fit to existing protocol object like an "OAM_SPEC" may be a better fit to existing protocol
elements. elements.
The authors of this document favor the first alternative (adding new The authors of this document favor the first alternative (adding new
TLVs to LSP_ATTRIBTES/LSP_REQUIRED_ATTRIBUTES. However, which TLVs to LSP_ATTRIBTES/LSP_REQUIRED_ATTRIBUTES. However, which
alternative to select for standardization is up for the working group alternative to select for standardization is up for the working group
to decide. In any case, the information to be carried would be the to decide. In any case, the information to be carried would be the
same or very similar for both alternatives. same or very similar for both alternatives.
7. References 8. References
[GELS-Framework] [GELS-Framework]
"GMPLS Ethernet Label Switching Architecture and "GMPLS Ethernet Label Switching Architecture and
Framework", Internet Draft, work in progress. Framework", Internet Draft, work in progress.
[GMPLS-OAM] [GMPLS-OAM]
"OAM Requirements for Generalized Multi-Protocol Label "OAM Requirements for Generalized Multi-Protocol Label
Switching (GMPLS) Networks", Internet Draft, work in Switching (GMPLS) Networks", Internet Draft, work in
progress. progress.
[HOP_ATTR]
Kern, A. and A. Takacs, "Encoding of Attributes of LSP
hops using RSVP-TE", Internet-draft Work in progress,
October 2009.
[IEEE-CFM] [IEEE-CFM]
"IEEE 802.1ag, Draft Standard for Connectivity Fault "IEEE 802.1ag, Draft Standard for Connectivity Fault
Management", work in progress. Management", work in progress.
[IEEE-PBBTE] [IEEE-PBBTE]
"IEEE 802.1Qay Draft Standard for Provider Backbone "IEEE 802.1Qay Draft Standard for Provider Backbone
Bridging Traffic Engineering", work in progress. Bridging Traffic Engineering", work in progress.
[MPLS-TP-FWK] [MPLS-TP-FWK]
"A Framework for MPLS in Transport Networks", Internet "A Framework for MPLS in Transport Networks", Internet
skipping to change at page 22, line 51 skipping to change at page 21, line 46
Signaling Functional Description", RFC 3471, January 2003. Signaling Functional Description", RFC 3471, January 2003.
[RFC3473] "Generalized Multi-Protocol Label Switching (GMPLS) [RFC3473] "Generalized Multi-Protocol Label Switching (GMPLS)
Signaling Resource ReserVation Protocol-Traffic Signaling Resource ReserVation Protocol-Traffic
Engineering (RSVP-TE) Extensions", RFC 3473, January 2003. Engineering (RSVP-TE) Extensions", RFC 3473, January 2003.
[RFC4377] "Operations and Management (OAM) Requirements for Multi- [RFC4377] "Operations and Management (OAM) Requirements for Multi-
Protocol Label Switched (MPLS) Networks", RFC 4377, Protocol Label Switched (MPLS) Networks", RFC 4377,
February 2006. February 2006.
[RFC4420] "Encoding of Attributes for Multiprotocol Label Switching [RFC5420] "Encoding of Attributes for Multiprotocol Label Switching
(MPLS) Label Switched Path (LSP) Establishment Using (MPLS) Label Switched Path (LSP) Establishment Using
Resource ReserVation Protocol-Traffic Engineering Resource ReserVation Protocol-Traffic Engineering
(RSVP-TE)", RFC 4420, February 2006. (RSVP-TE)", RFC 5420, February 2009.
Authors' Addresses Authors' Addresses
Attila Takacs Attila Takacs
Ericsson Ericsson
Laborc u. 1. Laborc u. 1.
Budapest, 1037 Budapest, 1037
Hungary Hungary
Email: attila.takacs@ericsson.com Email: attila.takacs@ericsson.com
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