draft-ietf-mpls-cr-ldp-05.txt   draft-ietf-mpls-cr-ldp-06.txt 
MPLS Working Group Bilel Jamoussi, Editor MPLS Working Group Bilel Jamoussi, Editor
Internet Draft Nortel Networks Corp. Internet Draft Nortel Networks Corp.
Expiration Date: August 2001 Expiration Date: May 2002
O. Aboul-Magd, L. Andersson, P. Ashwood-Smith, O. Aboul-Magd, P. Ashwood-Smith,
F. Hellstrand, K. Sundell, Nortel Networks Corp. F. Hellstrand, K. Sundell, Nortel Networks Corp.
L. Andersson, Utfors
R. Callon, Juniper Networks. R. Callon, Juniper Networks.
R. Dantu, L. Wu, Cisco Systems R. Dantu, L. Wu, Cisco Systems
P. Doolan, T. Worster, Ennovate Networks Corp. P. Doolan, T. Worster, Ennovate Networks Corp.
N. Feldman, IBM Corp. N. Feldman, IBM Corp.
A. Fredette, PhotonEx Corp. A. Fredette, PhotonEx Corp.
M. Girish, Atoga Systems M. Girish, Atoga Systems
E. Gray, Sandburst E. Gray, Sandburst
J. Halpern, Longitude Systems, Inc. J. Halpern, Longitude Systems, Inc.
J. Heinanen, Telia Finland J. Heinanen, Telia Finland
T. Kilty, Newbridge Networks, Inc. T. Kilty, Newbridge Networks, Inc.
A. Malis, Vivace Networks A. Malis, Vivace Networks
P. Vaananen, Nokia Telecommunications P. Vaananen, Nokia Telecommunications
February 2001 November 2001
Constraint-Based LSP Setup using LDP Constraint-Based LSP Setup using LDP
draft-ietf-mpls-cr-ldp-05.txt draft-ietf-mpls-cr-ldp-06.txt
Status of this Memo Status of this Memo
This document is an Internet-Draft and is in full conformance with This document is an Internet-Draft and is in full conformance 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
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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
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http://www.ietf.org/shadow.html. http://www.ietf.org/shadow.html.
Abstract Abstract
Label Distribution Protocol (LDP) is defined in [1] for distribution Label Distribution Protocol (LDP) is defined in [1] for distribution
of labels inside one MPLS domain. One of the most important of labels inside one MPLS domain. One of the most important
services that may be offered using MPLS in general and LDP in services that may be offered using MPLS in general and LDP in
particular is support for constraint-based routing of traffic across particular is support for constraint-based routing of traffic across
Jamoussi, et. al. draft-ietf-mpls-crldp-05.txt 1 Jamoussi, et. al. draft-ietf-mpls-crldp-06.txt 1
the routed network. Constraint-based routing offers the opportunity the routed network. Constraint-based routing offers the opportunity
to extend the information used to setup paths beyond what is to extend the information used to setup paths beyond what is
available for the routing protocol. For instance, an LSP can be available for the routing protocol. For instance, an LSP can be
setup based on explicit route constraints, QoS constraints, and setup based on explicit route constraints, QoS constraints, and
other constraints. Constraint-based routing (CR) is a mechanism used other constraints. Constraint-based routing (CR) is a mechanism used
to meet Traffic Engineering requirements that have been proposed by, to meet Traffic Engineering requirements that have been proposed by,
[2] and [3]. These requirements may be met by extending LDP for [2] and [3]. These requirements may be met by extending LDP for
support of constraint-based routed label switched paths (CR-LSPs). support of constraint-based routed label switched paths (CR-LSPs).
Other uses for CR-LSPs include MPLS-based VPNs [4]. More information Other uses for CR-LSPs include MPLS-based VPNs [4]. More information
about the applicability of CR-LDP can be found in [5]. about the applicability of CR-LDP can be found in [5].
This draft specifies mechanisms and TLVs for support of CR-LSPs This draft specifies mechanisms and TLVs for support of CR-LSPs
using LDP. using LDP.
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL
NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL"
in this document are to be interpreted as described in RFC 2119 [6]. in this document are to be interpreted as described in RFC 2119 [6].
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Table of Contents Table of Contents
1. Introduction....................................................4 1. Introduction....................................................4
2. Constraint-based Routing Overview...............................4 2. Constraint-based Routing Overview...............................4
2.1 Strict and Loose Explicit Routes...............................5 2.1 Strict and Loose Explicit Routes...............................5
2.2 Traffic Characteristics........................................5 2.2 Traffic Characteristics........................................5
2.3 Pre-emption....................................................6 2.3 Pre-emption....................................................6
2.4 Route Pinning..................................................6 2.4 Route Pinning..................................................6
2.5 Resource Class.................................................6 2.5 Resource Class.................................................6
3. Solution Overview...............................................6 3. Solution Overview...............................................6
skipping to change at line 127 skipping to change at line 128
4.9 Route Pinning TLV.............................................25 4.9 Route Pinning TLV.............................................25
4.10 CR-LSP FEC Element...........................................26 4.10 CR-LSP FEC Element...........................................26
5. IANA Considerations............................................26 5. IANA Considerations............................................26
5.1 TLV Type Name Space...........................................26 5.1 TLV Type Name Space...........................................26
5.2 FEC Type Name Space...........................................27 5.2 FEC Type Name Space...........................................27
5.3 Status Code Space.............................................27 5.3 Status Code Space.............................................27
6. Security.......................................................28 6. Security.......................................................28
7. Acknowledgments................................................28 7. Acknowledgments................................................28
8. Intellectual Property Consideration............................28 8. Intellectual Property Consideration............................28
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9. References.....................................................28 9. References.....................................................28
10. AuthorĂs Addresses............................................29 10. Author's Addresses............................................29
Appendix A: CR-LSP Establishment Examples.........................31 Appendix A: CR-LSP Establishment Examples.........................31
A.1 Strict Explicit Route Example.................................31 A.1 Strict Explicit Route Example.................................31
A.2 Node Groups and Specific Nodes Example........................32 A.2 Node Groups and Specific Nodes Example........................32
Appendix B. QoS Service Examples..................................35 Appendix B. QoS Service Examples..................................35
B.1 Service Examples..............................................35 B.1 Service Examples..............................................35
B.2 Establishing CR-LSP Supporting Real-Time Applications.........36 B.2 Establishing CR-LSP Supporting Real-Time Applications.........36
B.3 Establishing CR-LSP Supporting Delay Insensitive Applications.37 B.3 Establishing CR-LSP Supporting Delay Insensitive Applications.37
1. Introduction 1. Introduction
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of CR-LSP path setup. Appendix B provides Service Definition of CR-LSP path setup. Appendix B provides Service Definition
Examples. Examples.
2. Constraint-based Routing Overview 2. Constraint-based Routing Overview
Constraint-based routing is a mechanism that supports the Traffic Constraint-based routing is a mechanism that supports the Traffic
Engineering requirements defined in [3]. Explicit Routing is a Engineering requirements defined in [3]. Explicit Routing is a
subset of the more general constraint-based routing where the subset of the more general constraint-based routing where the
constraint is the explicit route (ER). Other constraints are defined constraint is the explicit route (ER). Other constraints are defined
Jamoussi, et. al. draft-ietf-mpls-crldp-05.txt 4 Jamoussi, et. al. draft-ietf-mpls-crldp-06.txt 4
to provide a network operator with control over the path taken by an to provide a network operator with control over the path taken by an
LSP. This section is an overview of the various constraints LSP. This section is an overview of the various constraints
supported by this specification. supported by this specification.
Like any other LSP a CR-LSP is a path through an MPLS network. The Like any other LSP a CR-LSP is a path through an MPLS network. The
difference is that while other paths are setup solely based on difference is that while other paths are setup solely based on
information in routing tables or from a management system, the information in routing tables or from a management system, the
constraint-based route is calculated at one point at the edge of constraint-based route is calculated at one point at the edge of
network based on criteria, including but not limited to routing network based on criteria, including but not limited to routing
information. The intention is that this functionality shall give information. The intention is that this functionality shall give
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including all of the abstract nodes, with the specified operations including all of the abstract nodes, with the specified operations
occurring along that path. occurring along that path.
2.2 Traffic Characteristics 2.2 Traffic Characteristics
The traffic characteristics of a path are described in the Traffic The traffic characteristics of a path are described in the Traffic
Parameters TLV in terms of a peak rate, committed rate, and service Parameters TLV in terms of a peak rate, committed rate, and service
granularity. The peak and committed rates describe the bandwidth granularity. The peak and committed rates describe the bandwidth
constraints of a path while the service granularity can be used to constraints of a path while the service granularity can be used to
specify a constraint on the delay variation that the CR-LDP MPLS specify a constraint on the delay variation that the CR-LDP MPLS
domain may introduce to a pathĂs traffic. domain may introduce to a path's traffic.
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2.3 Pre-emption 2.3 Pre-emption
CR-LDP signals the resources required by a path on each hop of the CR-LDP signals the resources required by a path on each hop of the
route. If a route with sufficient resources can not be found, route. If a route with sufficient resources can not be found,
existing paths may be rerouted to reallocate resources to the new existing paths may be rerouted to reallocate resources to the new
path. This is the process of path pre-emption. Setup and holding path. This is the process of path pre-emption. Setup and holding
priorities are used to rank existing paths (holding priority) and priorities are used to rank existing paths (holding priority) and
the new path (setup priority) to determine if the new path can pre- the new path (setup priority) to determine if the new path can pre-
empt an existing path. empt an existing path.
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The setup and holding priority values range from zero (0) to seven The setup and holding priority values range from zero (0) to seven
(7). The value zero (0) is the priority assigned to the most (7). The value zero (0) is the priority assigned to the most
important path. It is referred to as the highest priority. Seven (7) important path. It is referred to as the highest priority. Seven (7)
is the priority for the least important path. The use of default is the priority for the least important path. The use of default
priority values is an aspect of network policy. The recommended priority values is an aspect of network policy. The recommended
default value is (4). default value is (4).
The setupPriority of a CR-LSP should not be higher (numerically The setupPriority of a CR-LSP should not be higher (numerically
less) than its holdingPriority since it might bump an LSP and be less) than its holdingPriority since it might bump an LSP and be
bumped by the next "equivalent÷ request. bumped by the next "equivalent" request.
2.4 Route Pinning 2.4 Route Pinning
Route pinning is applicable to segments of an LSP that are loosely Route pinning is applicable to segments of an LSP that are loosely
routed - i.e. those segments which are specified with a next hop routed - i.e. those segments which are specified with a next hop
with the ÷L÷ bit set or where the next hop is an ÷abstract node÷. A with the "L" bit set or where the next hop is an "abstract node". A
CR-LSP may be setup using route pinning if it is undesirable to CR-LSP may be setup using route pinning if it is undesirable to
change the path used by an LSP even when a better next hop becomes change the path used by an LSP even when a better next hop becomes
available at some LSR along the loosely routed portion of the LSP. available at some LSR along the loosely routed portion of the LSP.
2.5 Resource Class 2.5 Resource Class
The network operator may classify network resources in various ways. The network operator may classify network resources in various ways.
These classes are also known as "colors÷ or "administrative groups÷. These classes are also known as "colors" or "administrative groups".
When a CR-LSP is being established, itĂs necessary to indicate which When a CR-LSP is being established, it's necessary to indicate which
resource classes the CR-LSP can draw from. resource classes the CR-LSP can draw from.
3. Solution Overview 3. Solution Overview
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CR-LSP over LDP Specification is designed with the following goals: CR-LSP over LDP Specification is designed with the following goals:
1. Meet the requirements outlined in [3] for performing traffic 1. Meet the requirements outlined in [3] for performing traffic
engineering and provide a solid foundation for performing more engineering and provide a solid foundation for performing more
general constraint-based routing. general constraint-based routing.
2. Build on already specified functionality that meets the 2. Build on already specified functionality that meets the
requirements whenever possible. Hence, this specification is requirements whenever possible. Hence, this specification is
based on [1]. based on [1].
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- Use of Basic and/or Extended Discovery Mechanisms. - Use of Basic and/or Extended Discovery Mechanisms.
- Use of the Label Request Message defined in [1] in downstream on - Use of the Label Request Message defined in [1] in downstream on
demand label advertisement mode with ordered control. demand label advertisement mode with ordered control.
- Use of the Label Mapping Message defined in [1] in downstream on - Use of the Label Mapping Message defined in [1] in downstream on
demand mode with ordered control. demand mode with ordered control.
- Use of the Notification Message defined in [1]. - Use of the Notification Message defined in [1].
- Use of the Withdraw and Release Messages defined in [1]. - Use of the Withdraw and Release Messages defined in [1].
- Use of the Loop Detection (in the case of loosely routed - Use of the Loop Detection (in the case of loosely routed
segments of a CR-LSP) mechanisms defined in [1]. segments of a CR-LSP) mechanisms defined in [1].
In addition, the following functionality is added to whatĂs defined In addition, the following functionality is added to what's defined
in [1]: in [1]:
- The Label Request Message used to setup a CR-LSP includes one or - The Label Request Message used to setup a CR-LSP includes one or
more CR-TLVs defined in Section 4. For instance, the Label Request more CR-TLVs defined in Section 4. For instance, the Label Request
Message may include the ER-TLV. Message may include the ER-TLV.
- An LSR implicitly infers ordered control from the existence of - An LSR implicitly infers ordered control from the existence of
one or more CR-TLVs in the Label Request Message. This means that one or more CR-TLVs in the Label Request Message. This means that
the LSR can still be configured for independent control for LSPs the LSR can still be configured for independent control for LSPs
established as a result of dynamic routing. However, when a Label established as a result of dynamic routing. However, when a Label
Request Message includes one or more of the CR-TLVs, then ordered Request Message includes one or more of the CR-TLVs, then ordered
control is used to setup the CR-LSP. Note that this is also true control is used to setup the CR-LSP. Note that this is also true
for the loosely routed parts of a CR-LSP. for the loosely routed parts of a CR-LSP.
- New status codes are defined to handle error notification for - New status codes are defined to handle error notification for
failure of established paths specified in the CR-TLVs. failure of established paths specified in the CR-TLVs. All of the
new status codes require that the F bit be set.
Optional TLVs MUST be implemented to be compliant with the protocol. Optional TLVs MUST be implemented to be compliant with the protocol.
However, they are optionally carried in the CR-LDP messages to However, they are optionally carried in the CR-LDP messages to
signal certain characteristics of the CR-LSP being established or signal certain characteristics of the CR-LSP being established or
modified. modified.
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Examples of CR-LSP establishment are given in Appendix A to Examples of CR-LSP establishment are given in Appendix A to
illustrate how the mechanisms described in this draft work. illustrate how the mechanisms described in this draft work.
3.1 Required Messages and TLVs 3.1 Required Messages and TLVs
Any Messages, TLVs, and procedures not defined explicitly in this Any Messages, TLVs, and procedures not defined explicitly in this
document are defined in the LDP Specification [1]. The reader can document are defined in the LDP Specification [1]. The reader can
use [7] as an informational document about the state transitions, use [7] as an informational document about the state transitions,
which relate to CR-LDP messages. which relate to CR-LDP messages.
The following subsections are meant as a cross-reference to the [1] The following subsections are meant as a cross-reference to the [1]
document and indication of additional functionality beyond whatĂs document and indication of additional functionality beyond what's
defined in [1] where necessary. defined in [1] where necessary.
Note that use of the Status TLV is not limited to Notification Note that use of the Status TLV is not limited to Notification
messages as specified in Section 3.4.6 of [1]. A message other than messages as specified in Section 3.4.6 of [1]. A message other than
a Notification message may carry a Status TLV as an Optional a Notification message may carry a Status TLV as an Optional
Parameter. When a message other than a Notification carries a Parameter. When a message other than a Notification carries a
Status TLV the U-bit of the Status TLV should be set to 1 to Status TLV the U-bit of the Status TLV should be set to 1 to
indicate that the receiver should silently discard the TLV if indicate that the receiver should silently discard the TLV if
unprepared to handle it. unprepared to handle it.
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|0| Label Request (0x0401) | Message Length | |0| Label Request (0x0401) | Message Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Message ID | | Message ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| FEC TLV | | FEC TLV |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| LSPID TLV (CR-LDP, mandatory) | | LSPID TLV (CR-LDP, mandatory) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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| ER-TLV (CR-LDP, optional) | | ER-TLV (CR-LDP, optional) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Traffic TLV (CR-LDP, optional) | | Traffic TLV (CR-LDP, optional) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Pinning TLV (CR-LDP, optional) | | Pinning TLV (CR-LDP, optional) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Resource Class TLV (CR-LDP, optional) | | Resource Class TLV (CR-LDP, optional) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Pre-emption TLV (CR-LDP, optional) | | Pre-emption TLV (CR-LDP, optional) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Label Request Message ID TLV | | Label Request Message ID TLV |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| LSPID TLV (CR-LDP, optional) | | LSPID TLV (CR-LDP, optional) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Traffic TLV (CR-LDP, optional) | | Traffic TLV (CR-LDP, optional) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3.4 Notification Message 3.4 Notification Message
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The Notification Message is as defined in Section 3.5.1 of [1] and The Notification Message is as defined in Section 3.5.1 of [1] and
the Status TLV encoding is as defined in Section 3.4.6 of [1]. the Status TLV encoding is as defined in Section 3.4.6 of [1].
Establishment of an CR-LSP may fail for a variety of reasons. All Establishment of an CR-LSP may fail for a variety of reasons. All
such failures are considered advisory conditions and they are such failures are considered advisory conditions and they are
signaled by the Notification Message. signaled by the Notification Message.
Notification Messages carry Status TLVs to specify events being Notification Messages carry Status TLVs to specify events being
signaled. New status codes are defined in Section 4.11 to signal signaled. New status codes are defined in Section 4.11 to signal
error notifications associated with the establishment of a CR-LSP error notifications associated with the establishment of a CR-LSP
and the processing of the CR-TLV. and the processing of the CR-TLV. All of the new status codes
require that the F bit be set.
The Notification Message MAY carry the LSPID TLV of the The Notification Message MAY carry the LSPID TLV of the
corresponding CR-LSP. corresponding CR-LSP.
Notification Messages MUST be forwarded toward the LSR originating Notification Messages MUST be forwarded toward the LSR originating
the Label Request at each hop and at any time that procedures in the Label Request at each hop and at any time that procedures in
this specification - or in [1] - specify sending of a Notification this specification - or in [1] - specify sending of a Notification
Message in response to a Label Request Message. Message in response to a Label Request Message.
The encoding of the notification message is as follows: The encoding of the notification message is as follows:
skipping to change at line 501 skipping to change at line 504
TLVs (CR-TLVs) defined in this section. If needed, other constraints TLVs (CR-TLVs) defined in this section. If needed, other constraints
can be supported later through the definition of new TLVs. In this can be supported later through the definition of new TLVs. In this
specification, the following TLVs are defined: specification, the following TLVs are defined:
- Explicit Route TLV - Explicit Route TLV
- Explicit Route Hop TLV - Explicit Route Hop TLV
- Traffic Parameters TLV - Traffic Parameters TLV
- Preemption TLV - Preemption TLV
- LSPID TLV - LSPID TLV
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- Route Pinning TLV - Route Pinning TLV
- Resource Class TLV - Resource Class TLV
- CR-LSP FEC TLV - CR-LSP FEC TLV
4.1 Explicit Route TLV (ER-TLV) 4.1 Explicit Route TLV (ER-TLV)
The ER-TLV is an object that specifies the path to be taken by the The ER-TLV is an object that specifies the path to be taken by the
LSP being established. It is composed of one or more Explicit Route LSP being established. It is composed of one or more Explicit Route
Hop TLVs (ER-Hop TLVs) defined in Section 4.2. Hop TLVs (ER-Hop TLVs) defined in Section 4.2.
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ER-Hop TLVs ER-Hop TLVs
One or more ER-Hop TLVs defined in Section 4.2. One or more ER-Hop TLVs defined in Section 4.2.
4.2 Explicit Route Hop TLV (ER-Hop TLV) 4.2 Explicit Route Hop TLV (ER-Hop TLV)
The contents of an ER-TLV are a series of variable length ER-Hop The contents of an ER-TLV are a series of variable length ER-Hop
TLVs. TLVs.
A node receiving a label request message including an ER-Hop type A node receiving a label request message including an ER-Hop type
that is not supported MUST not progress the label request message to that is not supported MUST not progress the label request message to
the downstream LSR and MUST send back a "No Route÷ Notification the downstream LSR and MUST send back a "No Route" Notification
Message. Message.
Each ER-Hop TLV has the form: Each ER-Hop TLV has the form:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|0|0| Type | Length | |0|0| Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|L| Content // | |L| Content // |
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
ER-Hop Type ER-Hop Type
A fourteen-bit field carrying the type of the ER-Hop contents. A fourteen-bit field carrying the type of the ER-Hop contents.
Currently defined values are: Currently defined values are:
Value Type Value Type
------ ------------------------ ------ ------------------------
0x0801 IPv4 prefix 0x0801 IPv4 prefix
0x0802 IPv6 prefix 0x0802 IPv6 prefix
0x0803 Autonomous system number 0x0803 Autonomous system number
0x0804 LSPID 0x0804 LSPID
Length Length
Specifies the length of the value field in bytes. Specifies the length of the value field in bytes.
L bit L bit
The L bit in the ER-Hop is a one-bit attribute. If the L bit The L bit in the ER-Hop is a one-bit attribute. If the L bit
is set, then the value of the attribute is "loose.÷ Otherwise, is set, then the value of the attribute is "loose." Otherwise,
the value of the attribute is "strict.÷ For brevity, we say the value of the attribute is "strict." For brevity, we say
that if the value of the ER-Hop attribute is loose then it is a that if the value of the ER-Hop attribute is loose then it is a
"loose ER-Hop.÷ Otherwise, itĂs a "strict ER-Hop.÷ Further, "loose ER-Hop." Otherwise, it's a "strict ER-Hop." Further,
we say that the abstract node of a strict or loose ER-Hop is a we say that the abstract node of a strict or loose ER-Hop is a
strict or a loose node, respectively. Loose and strict nodes strict or a loose node, respectively. Loose and strict nodes
are always interpreted relative to their prior abstract nodes. are always interpreted relative to their prior abstract nodes.
The path between a strict node and its prior node MUST include The path between a strict node and its prior node MUST include
only network nodes from the strict node and its prior abstract only network nodes from the strict node and its prior abstract
node. node.
The path between a loose node and its prior node MAY include The path between a loose node and its prior node MAY include
other network nodes, which are not part of the strict node or other network nodes, which are not part of the strict node or
its prior abstract node. its prior abstract node.
skipping to change at line 608 skipping to change at line 611
Parameter values. Parameter values.
A Traffic Parameters TLV, is used to signal the Traffic Parameter A Traffic Parameters TLV, is used to signal the Traffic Parameter
values. The Traffic Parameters are defined in the subsequent values. The Traffic Parameters are defined in the subsequent
sections. sections.
The Traffic Parameters TLV contains a Flags field, a Frequency, a The Traffic Parameters TLV contains a Flags field, a Frequency, a
Weight, and the five Traffic Parameters PDR, PBS, CDR, CBS, EBS. Weight, and the five Traffic Parameters PDR, PBS, CDR, CBS, EBS.
The Traffic Parameters TLV is shown below: The Traffic Parameters TLV is shown below:
Jamoussi, et. al. draft-ietf-mpls-crldp-05.txt 12 Jamoussi, et. al. draft-ietf-mpls-crldp-06.txt 12
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|0|0| Type = 0x0810 | Length = 24 | |0|0| Type = 0x0810 | Length = 24 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Flags | Frequency | Reserved | Weight | | Flags | Frequency | Reserved | Weight |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Peak Data Rate (PDR) | | Peak Data Rate (PDR) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Peak Burst Size (PBS) | | Peak Burst Size (PBS) |
skipping to change at line 662 skipping to change at line 665
Parameter. The Negotiable Flag value zero denotes NotNegotiable Parameter. The Negotiable Flag value zero denotes NotNegotiable
and value one denotes Negotiable. and value one denotes Negotiable.
Frequency Frequency
The Frequency field is coded as an 8 bit unsigned integer with The Frequency field is coded as an 8 bit unsigned integer with
the following code points defined: the following code points defined:
0- Unspecified 0- Unspecified
1- Frequent 1- Frequent
Jamoussi, et. al. draft-ietf-mpls-crldp-05.txt 13 Jamoussi, et. al. draft-ietf-mpls-crldp-06.txt 13
2- VeryFrequent 2- VeryFrequent
3-255 - Reserved 3-255 - Reserved
Reserved - Zero on transmission. Ignored on receipt. Reserved - Zero on transmission. Ignored on receipt.
Weight Weight
An 8 bit unsigned integer indicating the weight of the CR-LSP. An 8 bit unsigned integer indicating the weight of the CR-LSP.
Valid weight values are from 1 to 255. The value 0 means that Valid weight values are from 1 to 255. The value 0 means that
weight is not applicable for the CR-LSP. weight is not applicable for the CR-LSP.
Traffic Parameters Traffic Parameters
skipping to change at line 716 skipping to change at line 719
ingress to the MPLS domain. ingress to the MPLS domain.
The Peak Rate is defined in terms of the two Traffic Parameters PDR The Peak Rate is defined in terms of the two Traffic Parameters PDR
and PBS, see section 4.3.1.5 below. and PBS, see section 4.3.1.5 below.
4.3.1.3 Committed Rate 4.3.1.3 Committed Rate
The Committed Rate defines the rate that the MPLS domain commits to The Committed Rate defines the rate that the MPLS domain commits to
be available to the CR-LSP. be available to the CR-LSP.
Jamoussi, et. al. draft-ietf-mpls-crldp-05.txt 14 Jamoussi, et. al. draft-ietf-mpls-crldp-06.txt 14
The Committed Rate is defined in terms of the two Traffic Parameters The Committed Rate is defined in terms of the two Traffic Parameters
CDR and CBS, see section 4.3.1.6 below. CDR and CBS, see section 4.3.1.6 below.
4.3.1.4 Excess Burst Size 4.3.1.4 Excess Burst Size
The Excess Burst Size may be used at the edge of an MPLS domain for The Excess Burst Size may be used at the edge of an MPLS domain for
the purpose of traffic conditioning. The EBS MAY be used to measure the purpose of traffic conditioning. The EBS MAY be used to measure
the extent by which the traffic sent on a CR-LSP exceeds the the extent by which the traffic sent on a CR-LSP exceeds the
committed rate. committed rate.
skipping to change at line 753 skipping to change at line 756
- If Tp(t)-B >= 0, the packet is not in excess of the peak rate - If Tp(t)-B >= 0, the packet is not in excess of the peak rate
and Tp is decremented by B down to the minimum value of 0, else and Tp is decremented by B down to the minimum value of 0, else
- the packet is in excess of the peak rate and Tp is not - the packet is in excess of the peak rate and Tp is not
decremented. decremented.
Note that according to the above definition, a positive infinite Note that according to the above definition, a positive infinite
value of either PDR or PBS implies that arriving packets are never value of either PDR or PBS implies that arriving packets are never
in excess of the peak rate. in excess of the peak rate.
The actual implementation of an LSR doesnĂt need to be modeled The actual implementation of an LSR doesn't need to be modeled
according to the above formal token bucket specification. according to the above formal token bucket specification.
4.3.1.6 Committed Data Rate Token Bucket 4.3.1.6 Committed Data Rate Token Bucket
The committed rate of a CR-LSP is specified in terms of a token The committed rate of a CR-LSP is specified in terms of a token
bucket C with rate CDR. The extent by which the offered rate bucket C with rate CDR. The extent by which the offered rate
exceeds the committed rate MAY be measured in terms of another token exceeds the committed rate MAY be measured in terms of another token
bucket E, which also operates at rate CDR. The maximum size of the bucket E, which also operates at rate CDR. The maximum size of the
token bucket C is CBS and the maximum size of the token bucket E is token bucket C is CBS and the maximum size of the token bucket E is
EBS. EBS.
The token buckets C and E are initially (at time 0) full, i.e., the The token buckets C and E are initially (at time 0) full, i.e., the
token count Tc(0) = CBS and the token count Te(0) = EBS. token count Tc(0) = CBS and the token count Te(0) = EBS.
Jamoussi, et. al. draft-ietf-mpls-crldp-05.txt 15 Jamoussi, et. al. draft-ietf-mpls-crldp-06.txt 15
Thereafter, the token counts Tc and Te are updated CDR times per Thereafter, the token counts Tc and Te are updated CDR times per
second as follows: second as follows:
- If Tc is less than CBS, Tc is incremented by one, else - If Tc is less than CBS, Tc is incremented by one, else
- if Te is less then EBS, Te is incremented by one, else - if Te is less then EBS, Te is incremented by one, else
neither Tc nor Te is incremented. neither Tc nor Te is incremented.
When a packet of size B bytes arrives at time t, the following When a packet of size B bytes arrives at time t, the following
happens: happens:
skipping to change at line 796 skipping to change at line 799
- the packet is in excess of both the Committed Rate and the EBS - the packet is in excess of both the Committed Rate and the EBS
and neither Tc nor Te is decremented. and neither Tc nor Te is decremented.
Note that according to the above specification, a CDR value of Note that according to the above specification, a CDR value of
positive infinity implies that arriving packets are never in excess positive infinity implies that arriving packets are never in excess
of either the Committed Rate or EBS. A positive infinite value of of either the Committed Rate or EBS. A positive infinite value of
either CBS or EBS implies that the respective limit cannot be either CBS or EBS implies that the respective limit cannot be
exceeded. exceeded.
The actual implementation of an LSR doesnĂt need to be modeled The actual implementation of an LSR doesn't need to be modeled
according to the above formal specification. according to the above formal specification.
4.3.1.7 Weight 4.3.1.7 Weight
The weight determines the CR-LSPĂs relative share of the possible The weight determines the CR-LSP's relative share of the possible
excess bandwidth above its committed rate. The definition of excess bandwidth above its committed rate. The definition of
"relative share÷ is MPLS domain specific. "relative share" is MPLS domain specific.
4.3.2 Procedures 4.3.2 Procedures
4.3.2.1 Label Request Message 4.3.2.1 Label Request Message
If an LSR receives an incorrectly encoded Traffic Parameters TLV in If an LSR receives an incorrectly encoded Traffic Parameters TLV in
which the value of PDR is less than the value of CDR then it MUST which the value of PDR is less than the value of CDR then it MUST
send a Notification Message including the Status code "Traffic send a Notification Message including the Status code "Traffic
Parameters Unavailable÷ to the upstream LSR from which it received Parameters Unavailable" to the upstream LSR from which it received
the erroneous message. the erroneous message.
If a Traffic Parameter is indicated as Negotiable in the Label If a Traffic Parameter is indicated as Negotiable in the Label
Request Message by the corresponding Negotiable Flag then an LSR MAY Request Message by the corresponding Negotiable Flag then an LSR MAY
replace the Traffic Parameter value with a smaller value. replace the Traffic Parameter value with a smaller value.
Jamoussi, et. al. draft-ietf-mpls-crldp-05.txt 16 Jamoussi, et. al. draft-ietf-mpls-crldp-06.txt 16
If the Weight is indicated as Negotiable in the Label Request If the Weight is indicated as Negotiable in the Label Request
Message by the corresponding Negotiable Flag then an LSR may replace Message by the corresponding Negotiable Flag then an LSR may replace
the Weight value with a lower value (down to 0). the Weight value with a lower value (down to 0).
If, after possible Traffic Parameter negotiation, an LSR can support If, after possible Traffic Parameter negotiation, an LSR can support
the CR-LSP Traffic Parameters then the LSR MUST reserve the the CR-LSP Traffic Parameters then the LSR MUST reserve the
corresponding resources for the CR-LSP. corresponding resources for the CR-LSP.
If, after possible Traffic Parameter negotiation, an LSR cannot If, after possible Traffic Parameter negotiation, an LSR cannot
support the CR-LSP Traffic Parameters then the LSR MUST send a support the CR-LSP Traffic Parameters then the LSR MUST send a
Notification Message that contains the "Resource Unavailable÷ status Notification Message that contains the "Resource Unavailable" status
code. code.
4.3.2.2 Label Mapping Message 4.3.2.2 Label Mapping Message
If an LSR receives an incorrectly encoded Traffic Parameters TLV in If an LSR receives an incorrectly encoded Traffic Parameters TLV in
which the value of PDR is less than the value of CDR then it MUST which the value of PDR is less than the value of CDR then it MUST
send a Label Release message containing the Status code "Traffic send a Label Release message containing the Status code "Traffic
Parameters Unavailable÷ to the LSR from which it received the Parameters Unavailable" to the LSR from which it received the
erroneous message. In addition, the LSP should send a Notification erroneous message. In addition, the LSP should send a Notification
Message upstream with the status code "Label Request Aborted÷. Message upstream with the status code 'Label Request Aborted'.
If the negotiation flag was set in the label request message, the If the negotiation flag was set in the label request message, the
egress LSR MUST include the (possibly negotiated) Traffic Parameters egress LSR MUST include the (possibly negotiated) Traffic Parameters
and Weight in the Label Mapping message. and Weight in the Label Mapping message.
The Traffic Parameters and the Weight in a Label Mapping message The Traffic Parameters and the Weight in a Label Mapping message
MUST be forwarded unchanged. MUST be forwarded unchanged.
An LSR SHOULD adjust the resources that it reserved for a CR-LSP An LSR SHOULD adjust the resources that it reserved for a CR-LSP
when it receives a Label Mapping Message if the Traffic Parameters when it receives a Label Mapping Message if the Traffic Parameters
differ from those in the corresponding Label Request Message. differ from those in the corresponding Label Request Message.
4.3.2.3 Notification Message 4.3.2.3 Notification Message
If an LSR receives a Notification Message for a CR-LSP, it SHOULD If an LSR receives a Notification Message for a CR-LSP, it SHOULD
release any resources that it possibly had reserved for the CR-LSP. release any resources that it possibly had reserved for the CR-LSP.
In addition, on receiving a Notification Message from a Downstream In addition, on receiving a Notification Message from a Downstream
LSR that is associated with a Label Request from an upstream LSR, LSR that is associated with a Label Request from an upstream LSR,
the local LSR MUST propagate the Notification message using the the local LSR MUST propagate the Notification message using the
procedures in [1]. procedures in [1]. Further the F bit MUST be set.
4.4 Preemption TLV 4.4 Preemption TLV
The defualt value of the setup and holding priorities should be in The defualt value of the setup and holding priorities should be in
the middle of the range (e.g., 4) so that this feature can be turned the middle of the range (e.g., 4) so that this feature can be turned
on gradually in an operational network by increasing or decreasing on gradually in an operational network by increasing or decreasing
the priority starting at the middle of the range. the priority starting at the middle of the range.
Since the Preemption TLV is an optional TLV, LSPs that are setup Since the Preemption TLV is an optional TLV, LSPs that are setup
without an explicitly signaled preemption TLV SHOULD be treated as without an explicitly signaled preemption TLV SHOULD be treated as
LSPs with the default setup and holding priorities (e.g., 4). LSPs with the default setup and holding priorities (e.g., 4).
Jamoussi, et. al. draft-ietf-mpls-crldp-05.txt 17 Jamoussi, et. al. draft-ietf-mpls-crldp-06.txt 17
When an established LSP is preempted, the LSR that initiates the When an established LSP is preempted, the LSR that initiates the
preemption sends a Withdraw Message upstream and a Release Message preemption sends a Withdraw Message upstream and a Release Message
downstream. downstream.
When an LSP in the process of being established (outstanding Label When an LSP in the process of being established (outstanding Label
Request without getting a Label Mapping back) is preempted, the LSR Request without getting a Label Mapping back) is preempted, the LSR
that initiates the preemption, sends a Notification Message upstream that initiates the preemption, sends a Notification Message upstream
and an Abort Message downstream. and an Abort Message downstream.
0 1 2 3 0 1 2 3
skipping to change at line 926 skipping to change at line 929
4.5 LSPID TLV 4.5 LSPID TLV
LSPID is a unique identifier of a CR-LSP within an MPLS network. LSPID is a unique identifier of a CR-LSP within an MPLS network.
The LSPID is composed of the ingress LSR Router ID (or any of its The LSPID is composed of the ingress LSR Router ID (or any of its
own Ipv4 addresses) and a Locally unique CR-LSP ID to that LSR. own Ipv4 addresses) and a Locally unique CR-LSP ID to that LSR.
The LSPID is useful in network management, in CR-LSP repair, and in The LSPID is useful in network management, in CR-LSP repair, and in
using an already established CR-LSP as a hop in an ER-TLV. using an already established CR-LSP as a hop in an ER-TLV.
Jamoussi, et. al. draft-ietf-mpls-crldp-05.txt 18 Jamoussi, et. al. draft-ietf-mpls-crldp-06.txt 18
An "action indicator flag÷ is carried in the LSPID TLV. This "action An "action indicator flag" is carried in the LSPID TLV. This "action
indicator flag÷ indicates explicitly the action that should be taken indicator flag" indicates explicitly the action that should be taken
if the LSP already exists on the LSR receiving the message. if the LSP already exists on the LSR receiving the message.
After a CR-LSP is set up, its bandwidth reservation may need to be After a CR-LSP is set up, its bandwidth reservation may need to be
changed by the network operator, due to the new requirements for the changed by the network operator, due to the new requirements for the
traffic carried on that CR-LSP. The "action indicator flag÷ is used traffic carried on that CR-LSP. The "action indicator flag" is used
indicate the need to modify the bandwidth and possibly other indicate the need to modify the bandwidth and possibly other
parameters of an established CR-LSP without service interruption. parameters of an established CR-LSP without service interruption.
This feature has application in dynamic network resources management This feature has application in dynamic network resources management
where traffic of different priorities and service classes is where traffic of different priorities and service classes is
involved. involved.
The procedure for the code point "modify÷ is defined in [8]. The The procedure for the code point "modify" is defined in [8]. The
procedures for other flags are FFS. procedures for other flags are FFS.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|0|0| Type = 0x0821 | Length = 4 | |0|0| Type = 0x0821 | Length = 4 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Reserved |ActFlg | Local CR-LSP ID | | Reserved |ActFlg | Local CR-LSP ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Ingress LSR Router ID | | Ingress LSR Router ID |
skipping to change at line 978 skipping to change at line 981
Reserved Reserved
Zero on transmission. Ignored on receipt. Zero on transmission. Ignored on receipt.
Local CR-LSP ID Local CR-LSP ID
The Local LSP ID is an identifier of the CR-LSP locally unique The Local LSP ID is an identifier of the CR-LSP locally unique
within the Ingress LSR originating the CR-LSP. within the Ingress LSR originating the CR-LSP.
Ingress LSR Router ID Ingress LSR Router ID
An LSR may use any of its own IPv4 addresses in this field. An LSR may use any of its own IPv4 addresses in this field.
Jamoussi, et. al. draft-ietf-mpls-crldp-05.txt 19 Jamoussi, et. al. draft-ietf-mpls-crldp-06.txt 19
4.6 Resource Class (Color) TLV 4.6 Resource Class (Color) TLV
The Resource Class as defined in [3] is used to specify which links The Resource Class as defined in [3] is used to specify which links
are acceptable by this CR-LSP. This information allows for the are acceptable by this CR-LSP. This information allows for the
networkĂs topology to be pruned. network's topology to be pruned.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|0|0| Type = 0x0822 | Length = 4 | |0|0| Type = 0x0822 | Length = 4 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| RsCls | | RsCls |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type Type
A fourteen-bit field carrying the value of the ResCls-TLV Type A fourteen-bit field carrying the value of the ResCls-TLV Type
= 0x0822. = 0x0822.
Length Length
Specifies the length of the value field in bytes = 4. Specifies the length of the value field in bytes = 4.
RsCls RsCls
The Resource Class bit mask indicating which of the 32 The Resource Class bit mask indicating which of the 32
"administrative groups÷ or "colors÷ of links the CR-LSP can "administrative groups" or "colors" of links the CR-LSP can
traverse. traverse.
4.7 ER-Hop semantics 4.7 ER-Hop semantics
4.7.1. ER-Hop 1: The IPv4 prefix 4.7.1. ER-Hop 1: The IPv4 prefix
The abstract node represented by this ER-Hop is the set of nodes, The abstract node represented by this ER-Hop is the set of nodes,
which have an IP address, which lies within this prefix. Note that which have an IP address, which lies within this prefix. Note that
a prefix length of 32 indicates a single IPv4 node. a prefix length of 32 indicates a single IPv4 node.
skipping to change at line 1033 skipping to change at line 1036
Type Type
A fourteen-bit field carrying the value of the ER-Hop 1, IPv4 A fourteen-bit field carrying the value of the ER-Hop 1, IPv4
Address, Type = 0x0801 Address, Type = 0x0801
Length Length
Specifies the length of the value field in bytes = 8. Specifies the length of the value field in bytes = 8.
L Bit L Bit
Jamoussi, et. al. draft-ietf-mpls-crldp-05.txt 20 Jamoussi, et. al. draft-ietf-mpls-crldp-06.txt 20
Set to indicate Loose hop. Set to indicate Loose hop.
Cleared to indicate a strict hop. Cleared to indicate a strict hop.
Reserved Reserved
Zero on transmission. Ignored on receipt. Zero on transmission. Ignored on receipt.
PreLen PreLen
Prefix Length 1-32 Prefix Length 1-32
IP Address IP Address
skipping to change at line 1086 skipping to change at line 1089
Zero on transmission. Ignored on receipt. Zero on transmission. Ignored on receipt.
PreLen PreLen
Prefix Length 1-128 Prefix Length 1-128
IPv6 address IPv6 address
A 128-bit unicast host address. A 128-bit unicast host address.
4.7.3. ER-Hop 3: The autonomous system number 4.7.3. ER-Hop 3: The autonomous system number
Jamoussi, et. al. draft-ietf-mpls-crldp-05.txt 21 Jamoussi, et. al. draft-ietf-mpls-crldp-06.txt 21
The abstract node represented by this ER-Hop is the set of nodes The abstract node represented by this ER-Hop is the set of nodes
belonging to the autonomous system. belonging to the autonomous system.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|0|0| 0x0803 | Length = 4 | |0|0| 0x0803 | Length = 4 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|L| Reserved | AS Number | |L| Reserved | AS Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
skipping to change at line 1140 skipping to change at line 1143
as part of its state information. This is due to the fact that the as part of its state information. This is due to the fact that the
upstream LSR needs only to keep the next ER-Hop and the LSPID and upstream LSR needs only to keep the next ER-Hop and the LSPID and
the downstream LSR needs only to keep the LSPID in order for each the downstream LSR needs only to keep the LSPID in order for each
end to be able to recognize that the same LSP is being identified. end to be able to recognize that the same LSP is being identified.
If the LSPID Hop is not the last hop in an ER-TLV, the LSR must If the LSPID Hop is not the last hop in an ER-TLV, the LSR must
remove the LSP-ID Hop and forward the remaining ER-TLV in a Label remove the LSP-ID Hop and forward the remaining ER-TLV in a Label
Request message using an LDP session established with the LSR that Request message using an LDP session established with the LSR that
is the specified CR-LSP's egress. That LSR will continue processing is the specified CR-LSP's egress. That LSR will continue processing
Jamoussi, et. al. draft-ietf-mpls-crldp-05.txt 22 Jamoussi, et. al. draft-ietf-mpls-crldp-06.txt 22
of the CR-LSP Label Request Message. The result is a tunneled, or of the CR-LSP Label Request Message. The result is a tunneled, or
stacked, CR-LSP. stacked, CR-LSP.
To support labels negotiated for tunneled CR-LSP segments, an LDP To support labels negotiated for tunneled CR-LSP segments, an LDP
session is required [1] between tunnel end points - possibly using session is required [1] between tunnel end points - possibly using
the existing CR-LSP. Use of the existence of the CR-LSP in lieu of the existing CR-LSP. Use of the existence of the CR-LSP in lieu of
a session, or other possible session-less approaches, is FFS. a session, or other possible session-less approaches, is FFS.
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
skipping to change at line 1192 skipping to change at line 1195
4.8.1. Selection of the next hop 4.8.1. Selection of the next hop
A Label Request Message containing an explicit route TLV must A Label Request Message containing an explicit route TLV must
determine the next hop for this path. Selection of this next hop determine the next hop for this path. Selection of this next hop
may involve a selection from a set of possible alternatives. The may involve a selection from a set of possible alternatives. The
mechanism for making a selection from this set is implementation mechanism for making a selection from this set is implementation
dependent and is outside of the scope of this specification. dependent and is outside of the scope of this specification.
Selection of particular paths is also outside of the scope of this Selection of particular paths is also outside of the scope of this
specification, but it is assumed that each node will make a best specification, but it is assumed that each node will make a best
Jamoussi, et. al. draft-ietf-mpls-crldp-05.txt 23 Jamoussi, et. al. draft-ietf-mpls-crldp-06.txt 23
effort attempt to determine a loop-free path. Note that such best effort attempt to determine a loop-free path. Note that such best
efforts may be overridden by local policy. efforts may be overridden by local policy.
To determine the next hop for the path, a node performs the To determine the next hop for the path, a node performs the
following steps: following steps:
1. The node receiving the Label Request Message must first 1. The node receiving the Label Request Message must first
evaluate the first ER-Hop. If the L bit is not set in the first evaluate the first ER-Hop. If the L bit is not set in the first
ER-Hop and if the node is not part of the abstract node described ER-Hop and if the node is not part of the abstract node described
by the first ER-Hop, it has received the message in error, and by the first ER-Hop, it has received the message in error, and
should return a "Bad Initial ER-Hop÷ error. If the L bit is set should return a "Bad Initial ER-Hop" error. If the L bit is set
and the local node is not part of the abstract node described by and the local node is not part of the abstract node described by
the first ER-Hop, the node selects a next hop that is along the the first ER-Hop, the node selects a next hop that is along the
path to the abstract node described by the first ER-Hop. If there path to the abstract node described by the first ER-Hop. If there
is no first ER-Hop, the message is also in error and the system is no first ER-Hop, the message is also in error and the system
should return a "Bad Explicit Routing TLV÷ error using a should return a "Bad Explicit Routing TLV" error using a
Notification Message sent upstream. Notification Message sent upstream.
2. If there is no second ER-Hop, this indicates the end of the 2. If there is no second ER-Hop, this indicates the end of the
explicit route. The explicit route TLV should be removed from the explicit route. The explicit route TLV should be removed from the
Label Request Message. This node may or may not be the end of Label Request Message. This node may or may not be the end of
the LSP. Processing continues with section 4.8.2, where a new the LSP. Processing continues with section 4.8.2, where a new
explicit route TLV may be added to the Label Request Message. explicit route TLV may be added to the Label Request Message.
3. If the node is also a part of the abstract node described by 3. If the node is also a part of the abstract node described by
the second ER-Hop, then the node deletes the first ER-Hop and the second ER-Hop, then the node deletes the first ER-Hop and
skipping to change at line 1234 skipping to change at line 1237
selects a particular next hop which is a member of the abstract selects a particular next hop which is a member of the abstract
node. The node then deletes the first ER-Hop and continues node. The node then deletes the first ER-Hop and continues
processing with section 4.8.2. processing with section 4.8.2.
5. Next, the node selects a next hop within the abstract node of 5. Next, the node selects a next hop within the abstract node of
the first ER-Hop that is along the path to the abstract node of the first ER-Hop that is along the path to the abstract node of
the second ER-Hop. If no such path exists then there are two the second ER-Hop. If no such path exists then there are two
cases: cases:
5.a If the second ER-Hop is a strict ER-Hop, then there is 5.a If the second ER-Hop is a strict ER-Hop, then there is
an error and the node should return a "Bad Strict Node÷ an error and the node should return a "Bad Strict Node"
error. error.
5.b Otherwise, if the second ER-Hop is a loose ER-Hop, then 5.b Otherwise, if the second ER-Hop is a loose ER-Hop, then
the node selects any next hop that is along the path to the the node selects any next hop that is along the path to the
next abstract node. If no path exists within the MPLS next abstract node. If no path exists within the MPLS
domain, then there is an error, and the node should return a domain, then there is an error, and the node should return a
"Bad loose node÷ error. "Bad loose node" error.
6. Finally, the node replaces the first ER-Hop with any ER-Hop 6. Finally, the node replaces the first ER-Hop with any ER-Hop
that denotes an abstract node containing the next hop. This is that denotes an abstract node containing the next hop. This is
Jamoussi, et. al. draft-ietf-mpls-crldp-05.txt 24 Jamoussi, et. al. draft-ietf-mpls-crldp-06.txt 24
necessary so that when the explicit route is received by the next necessary so that when the explicit route is received by the next
hop, it will be accepted. hop, it will be accepted.
7. Progress the Label Request Message to the next hop. 7. Progress the Label Request Message to the next hop.
4.8.2. Adding ER-Hops to the explicit route TLV 4.8.2. Adding ER-Hops to the explicit route TLV
After selecting a next hop, the node may alter the explicit route in After selecting a next hop, the node may alter the explicit route in
the following ways. the following ways.
skipping to change at line 1299 skipping to change at line 1302
P Bit P Bit
The P bit is set to 1 to indicate that route pinning is The P bit is set to 1 to indicate that route pinning is
requested. requested.
The P bit is set to 0 to indicate that route pinning is not The P bit is set to 0 to indicate that route pinning is not
requested requested
Reserved Reserved
Zero on transmission. Ignored on receipt. Zero on transmission. Ignored on receipt.
Jamoussi, et. al. draft-ietf-mpls-crldp-05.txt 25 Jamoussi, et. al. draft-ietf-mpls-crldp-06.txt 25
4.10 CR-LSP FEC Element 4.10 CR-LSP FEC Element
A new FEC element is introduced in this specification to support CR- A new FEC element is introduced in this specification to support CR-
LSPs. A FEC TLV containing a FEC of Element type CR-LSP (0x04) is a LSPs. A FEC TLV containing a FEC of Element type CR-LSP (0x04) is a
CR-LSP FEC TLV. The CR-LSP FEC Element is an opaque FEC to be used CR-LSP FEC TLV. The CR-LSP FEC Element is an opaque FEC to be used
only in Messages of CR-LSPs. only in Messages of CR-LSPs.
A single FEC element MUST be included in the Label Request Message. A single FEC element MUST be included in the Label Request Message.
The FEC Element SHOULD be the CR-LSP FEC Element. However, one of The FEC Element SHOULD be the CR-LSP FEC Element. However, one of
skipping to change at line 1354 skipping to change at line 1357
- TLV types. - TLV types.
- FEC types. - FEC types.
- Status codes. - Status codes.
The following sections provide guidelines for managing these name The following sections provide guidelines for managing these name
spaces. spaces.
5.1 TLV Type Name Space 5.1 TLV Type Name Space
Jamoussi, et. al. draft-ietf-mpls-crldp-05.txt 26 Jamoussi, et. al. draft-ietf-mpls-crldp-06.txt 26
RFC 3036 [1] defines the LDP TLV name space. This document further RFC 3036 [1] defines the LDP TLV name space. This document further
subdivides the range of RFC 3036 from that TLV space for TLVs subdivides the range of RFC 3036 from that TLV space for TLVs
associated with the CR-LDP in the range 0x0800 - 0x08FF. associated with the CR-LDP in the range 0x0800 - 0x08FF.
Following the policies outlined in [IANA], TLV types in this range Following the policies outlined in [IANA], TLV types in this range
are allocated through an IETF Consensus action. are allocated through an IETF Consensus action.
Initial values for this range are specified in the following table: Initial values for this range are specified in the following table:
TLV Type TLV Type
skipping to change at line 1379 skipping to change at line 1382
Autonomous System Number ER-Hop TLV 0x0803 Autonomous System Number ER-Hop TLV 0x0803
LSP-ID ER-Hop TLV 0x0804 LSP-ID ER-Hop TLV 0x0804
Traffic Parameters TLV 0x0810 Traffic Parameters TLV 0x0810
Preemption TLV 0x0820 Preemption TLV 0x0820
LSPID TLV 0x0821 LSPID TLV 0x0821
Resource Class TLV 0x0822 Resource Class TLV 0x0822
Route Pinning TLV 0x0823 Route Pinning TLV 0x0823
5.2 FEC Type Name Space 5.2 FEC Type Name Space
RFC 3036 defines the FEC Type TLV name space. This document further RFC 3036 defines the FEC Type name space. Further, RFC 3036 has
subdivides the range of RFC 3036 from that TLV space for TLVs assigned values 0x00 through 0x03. FEC types 0 through 127 are
associated with the CR-LDP in the range 100 - 116. available for assignment through IETF consensus action. This
specification makes the following additional assignment, using
Following the policies outlined in [IANA], TLV types in this range the policies outlined in [IANA]:
are allocated through an IETF Consensus action.
Initial values for this range are specified in the follwing table:
FEC Element TLV Type FEC Element Type
-------------------------------------- ---------- -------------------------------------- ----------
CR-LSP FEC Element TLV 0x0100 CR-LSP FEC Element 0x04
5.3 Status Code Space 5.3 Status Code Space
RFC 3036 defines the Status Code name space. This document further RFC 3036 defines the Status Code name space. This document further
subdivides the range of RFC 3036 from that TLV space for TLVs subdivides the range of RFC 3036 from that TLV space for TLVs
associated with the CR-LDP in the range 0x44000000 - 0x440000FF. associated with the CR-LDP in the range 0x04000000 - 0x040000FF.
Following the policies outlined in [IANA], TLV types in this range Following the policies outlined in [IANA], TLV types in this range
are allocated through an IETF Consensus action. are allocated through an IETF Consensus action.
Initial values for this range are specified in the follwing table: Initial values for this range are specified in the following table:
Status Code Type Status Code Type
-------------------------------------- ---------- -------------------------------------- ----------
Bad Explicit Routing TLV Error 0x44000001
Jamoussi, et. al. draft-ietf-mpls-crldp-05.txt 27 Bad Explicit Routing TLV Error 0x04000001
Bad Strict Node Error 0x44000002
Bad Loose Node Error 0x44000003 Jamoussi, et. al. draft-ietf-mpls-crldp-06.txt 27
Bad Initial ER-Hop Error 0x44000004 Bad Strict Node Error 0x04000002
Resource Unavailable 0x44000005 Bad Loose Node Error 0x04000003
Traffic Parameters Unavailable 0x44000006 Bad Initial ER-Hop Error 0x04000004
LSP Preempted 0x44000007 Resource Unavailable 0x04000005
Modify Request Not Supported 0x44000008 Traffic Parameters Unavailable 0x04000006
Setup Abort (Label Request Aborted in [1]) 0x04000015 LSP Preempted 0x04000007
Modify Request Not Supported 0x04000008
6. Security 6. Security
CR-LDP inherits the same security mechanism described in Section 4.0 CR-LDP inherits the same security mechanism described in Section 4.0
of [1] to protect against the introduction of spoofed TCP segments of [1] to protect against the introduction of spoofed TCP segments
into LDP session connection streams. into LDP session connection streams.
7. Acknowledgments 7. Acknowledgments
The messages used to signal the CR-LSP setup are based on the work The messages used to signal the CR-LSP setup are based on the work
skipping to change at line 1453 skipping to change at line 1453
2 Rosen et. al., "Multiprotocol Label Switching Architecture", 2 Rosen et. al., "Multiprotocol Label Switching Architecture",
RFC 3031, January 2001. RFC 3031, January 2001.
3 Awduche et. al., "Requirements for Traffic Engineering Over 3 Awduche et. al., "Requirements for Traffic Engineering Over
MPLS", RFC 2702, September 1999. MPLS", RFC 2702, September 1999.
4 Gleeson, et. al., "A Framework for IP Based Virtual Private 4 Gleeson, et. al., "A Framework for IP Based Virtual Private
Networks", RFC 2764, February 2000. Networks", RFC 2764, February 2000.
5 B. Jamoussi, et. al., ˘Applicability Statement for CR-LDP÷, work 5 B. Jamoussi, et. al., "Applicability Statement for CR-LDP", work
in progress, (draft-ietf-mpls-crldp-applic-01), June 2000. in progress, (draft-ietf-mpls-crldp-applic-01), June 2000.
6 S. Bradner, "Key words for use in RFCs to Indicate Requirement 6 S. Bradner, "Key words for use in RFCs to Indicate Requirement
Levels÷, RFC 2119, March 1997. Levels", RFC 2119, March 1997.
Jamoussi, et. al. draft-ietf-mpls-crldp-05.txt 28 Jamoussi, et. al. draft-ietf-mpls-crldp-06.txt 28
7 L. Wu, et. al., "LDP State Machine", work in progress, 7 L. Wu, et. al., "LDP State Machine", work in progress,
(draft-ietf-mpls-ldp-state-03), January 2000. (draft-ietf-mpls-ldp-state-03), January 2000.
8 J. Ash, et. al., "LSP Modification Using CR-LDP", work in 8 J. Ash, et. al., "LSP Modification Using CR-LDP", work in
progress, (draft-ietf-mpls-crlsp-modify-02), October 2000. progress, (draft-ietf-mpls-crlsp-modify-02), October 2000.
10. AuthorĂs Addresses 10. Author's Addresses
Osama S. Aboul-Magd Loa Andersson Osama S. Aboul-Magd Loa Andersson
Nortel Networks Nortel Networks Nortel Networks Utfors Bredband AB
P O Box 3511 Station C S:t Eriksgatan 115 P O Box 3511 Station C Rasundavagen 12 169 29
Ottawa, ON K1Y 4H7 PO Box 6701 Ottawa, ON K1Y 4H7 Solna
Canada 113 85 Stockholm Canada
Phone: +1 613 763-5827 Tel: +46 8 508 835 00 Phone: +1 613 763-5827 Tel: +46 8 5270 50 38
Osama@nortelnetworks.com Fax: +46 8 508 835 01 Osama@nortelnetworks.com loa.andersson@utfors.se
Loa_andersson@nortelnetworks.com
Peter Ashwood-Smith Ross Callon Peter Ashwood-Smith Ross Callon
Nortel Networks Juniper Networks Nortel Networks Juniper Networks
P O Box 3511 Station C 1194 North Mathilda Avenue, P O Box 3511 Station C 1194 North Mathilda Avenue,
Ottawa, ON K1Y 4H7 Sunnyvale, CA 94089 Ottawa, ON K1Y 4H7 Sunnyvale, CA 94089
Canada 978-692-6724 Canada 978-692-6724
Phone: +1 613 763-4534 rcallon@juniper.net Phone: +1 613 763-4534 rcallon@juniper.net
Petera@nortelnetworks.com Petera@nortelnetworks.com
Ram Dantu Paul Doolan Ram Dantu Paul Doolan
skipping to change at line 1512 skipping to change at line 1511
Phone: (978) 689-1610 Sterling, VA 20164 Phone: (978) 689-1610 Sterling, VA 20164
eric.gray@sandburst.com 703-433-0808 x207 eric.gray@sandburst.com 703-433-0808 x207
joel@longsys.com joel@longsys.com
Juha Heinanen Fiffi Hellstrand Juha Heinanen Fiffi Hellstrand
Telia Finland, Inc. Nortel Networks Telia Finland, Inc. Nortel Networks
Myyrmaentie 2 S:t Eriksgatan 115 Myyrmaentie 2 S:t Eriksgatan 115
01600 VANTAA PO Box 6701, 113 85 Stockholm 01600 VANTAA PO Box 6701, 113 85 Stockholm
Finland Sweden Finland Sweden
Jamoussi, et. al. draft-ietf-mpls-crldp-05.txt 29 Jamoussi, et. al. draft-ietf-mpls-crldp-06.txt 29
Tel: +358 41 500 4808 +46705593687 Tel: +358 41 500 4808 +46705593687
Jh@telia.fi fiffi@nortelnetworks.com Jh@telia.fi fiffi@nortelnetworks.com
Bilel Jamoussi Timothy E. Kilty Bilel Jamoussi Timothy E. Kilty
Nortel Networks Corp. Newbridge Networks, Inc. Nortel Networks Corp. Newbridge Networks, Inc.
600 Technology Park Drive 5 Corporate Drive 600 Technology Park Drive 5 Corporate Drive
Billerica, MA 01821 Andover, MA 01810 Billerica, MA 01821 Andover, MA 01810
USA USA USA USA
Phone: +1 978 288-4506 phone: 978 691-4656 Phone: +1 978 288-4506 phone: 978 691-4656
Jamoussi@nortelnetworks.com tkilty@northchurch.net Jamoussi@nortelnetworks.com tkilty@northchurch.net
skipping to change at line 1548 skipping to change at line 1547
Fax: +46 8 508 835 01 Fax: +46 8 508 835 01
Ksundell@nortelnetworks.com Ksundell@nortelnetworks.com
Tom Worster Liwen Wu Tom Worster Liwen Wu
Ennovate Networks Cisco Systems Ennovate Networks Cisco Systems
60 Codman Hill Rd 250 Apollo Drive 60 Codman Hill Rd 250 Apollo Drive
Boxborough Chelmsford, MA. 01824 Boxborough Chelmsford, MA. 01824
MA 01719 Tel: 978-244-3087. MA 01719 Tel: 978-244-3087.
tworster@ennovatenetworks.com liwwu@cisco.com tworster@ennovatenetworks.com liwwu@cisco.com
Jamoussi, et. al. draft-ietf-mpls-cr-ldp-04.txt 30 Jamoussi, et. al. draft-ietf-mpls-crldp-06.txt 30
Appendix A: CR-LSP Establishment Examples Appendix A: CR-LSP Establishment Examples
A.1 Strict Explicit Route Example A.1 Strict Explicit Route Example
This appendix provides an example for the setup of a strictly routed This appendix provides an example for the setup of a strictly routed
CR-LSP. In this example, a specific node represents each abstract CR-LSP. In this example, a specific node represents each abstract
node. node.
The sample network used here is a four node network with two edge The sample network used here is a four node network with two edge
skipping to change at line 1603 skipping to change at line 1602
Also, LSR2 is not a member of the abstract node described by the Also, LSR2 is not a member of the abstract node described by the
first ER-Hop <b>. first ER-Hop <b>.
Finally, the first ER-Hop <b> is a strict hop. Finally, the first ER-Hop <b> is a strict hop.
Therefore, processing section 4.8.2 does not result in the insertion Therefore, processing section 4.8.2 does not result in the insertion
of new ER-Hops. The selection of the next hop has been already done of new ER-Hops. The selection of the next hop has been already done
is step 4 of Section 4.8.1 and the processing of the ER-TLV is is step 4 of Section 4.8.1 and the processing of the ER-TLV is
Jamoussi, et. al. draft-ietf-mpls-cr-ldp-04.txt 31 Jamoussi, et. al. draft-ietf-mpls-crldp-06.txt 31
completed at LSR2. In this case, the Label Request Message including completed at LSR2. In this case, the Label Request Message including
the ER-TLV <b, c> is progressed by LSR2 to LSR3. the ER-TLV <b, c> is progressed by LSR2 to LSR3.
At LSR3, a similar processing to the ER-TLV takes place except that At LSR3, a similar processing to the ER-TLV takes place except that
the incoming ER-TLV = <b, c> and the outgoing ER-TLV is <c>. the incoming ER-TLV = <b, c> and the outgoing ER-TLV is <c>.
At LSR4, the following processing of section 4.8.1 takes place: At LSR4, the following processing of section 4.8.1 takes place:
1. The node LSR4 is part of the abstract node described by the 1. The node LSR4 is part of the abstract node described by the
first hop <c>. Therefore, the first step passes the test. Go to first hop <c>. Therefore, the first step passes the test. Go to
skipping to change at line 1657 skipping to change at line 1656
specific. specific.
The ingress LSR uses information provided by the management system The ingress LSR uses information provided by the management system
or the application and possibly also information from the routing or the application and possibly also information from the routing
database to calculate the explicit route and to create the Label database to calculate the explicit route and to create the Label
Request Message. Request Message.
The Label request message carries together with other necessary The Label request message carries together with other necessary
information an ER-TLV defining the explicitly routed path. In our information an ER-TLV defining the explicitly routed path. In our
Jamoussi, et. al. draft-ietf-mpls-cr-ldp-04.txt 32 Jamoussi, et. al. draft-ietf-mpls-crldp-06.txt 32
example the list of hops in the ER-Hop TLV is supposed to contain an example the list of hops in the ER-Hop TLV is supposed to contain an
abstract node representing a group of nodes, an abstract node abstract node representing a group of nodes, an abstract node
representing a specific node, another abstract node representing a representing a specific node, another abstract node representing a
group of nodes, and an abstract node representing a specific egress group of nodes, and an abstract node representing a specific egress
point. point.
In--{Group 1}--{Specific A}--{Group 2}--{Specific Out: B} In--{Group 1}--{Specific A}--{Group 2}--{Specific Out: B}
The ER-TLV contains four ER-Hop TLVs: The ER-TLV contains four ER-Hop TLVs:
1. An ER-Hop TLV that specifies a group of LSR valid for the 1. An ER-Hop TLV that specifies a group of LSR valid for the
skipping to change at line 1709 skipping to change at line 1708
5. It removes the first ER-Hop TLVs and sends a Label Request 5. It removes the first ER-Hop TLVs and sends a Label Request
Message to the specific node (A). Message to the specific node (A).
6. The specific node (A) recognizes itself in the first ER-Hop 6. The specific node (A) recognizes itself in the first ER-Hop
TLV. Removes the specific ER-Hop TLV. TLV. Removes the specific ER-Hop TLV.
7. It sends a Label Request Message to a node that is a member 7. It sends a Label Request Message to a node that is a member
of the group (Group 2) indicated in the ER-Hop TLV. of the group (Group 2) indicated in the ER-Hop TLV.
Jamoussi, et. al. draft-ietf-mpls-cr-ldp-04.txt 33 Jamoussi, et. al. draft-ietf-mpls-crldp-06.txt 33
8. The node that receives the message identifies itself as part 8. The node that receives the message identifies itself as part
of the group indicated in the first ER-Hop TLV, further it of the group indicated in the first ER-Hop TLV, further it
realizes that the specific egress node (B) is one of its next realizes that the specific egress node (B) is one of its next
hops. hops.
9. It sends a Label Request Message to the specific egress node 9. It sends a Label Request Message to the specific egress node
(B). (B).
10. The specific egress node (B) recognizes itself as the 10. The specific egress node (B) recognizes itself as the
egress for the CR-LSP, it returns a Label Mapping Message, that egress for the CR-LSP, it returns a Label Mapping Message, that
will traverse the same path as the Label Request Message in the will traverse the same path as the Label Request Message in the
opposite direction. opposite direction.
Jamoussi, et. al. draft-ietf-mpls-cr-ldp-04.txt 34 Jamoussi, et. al. draft-ietf-mpls-crldp-06.txt 34
Appendix B. QoS Service Examples Appendix B. QoS Service Examples
B.1 Service Examples B.1 Service Examples
Construction of an end-to-end service is the result of the rules Construction of an end-to-end service is the result of the rules
enforced at the edge and the treatment that packets receive at the enforced at the edge and the treatment that packets receive at the
network nodes. The rules define the traffic conditioning actions network nodes. The rules define the traffic conditioning actions
that are implemented at the edge and they include policing with that are implemented at the edge and they include policing with
pass, mark, and drop capabilities. The edge rules are expected tobe pass, mark, and drop capabilities. The edge rules are expected tobe
defined by the mutual agreements between the service providers and defined by the mutual agreements between the service providers and
skipping to change at line 1777 skipping to change at line 1776
ATM-VBR.3(nrt) PCR CDVT SCR MBS 0 Unspecified drop>PCR ATM-VBR.3(nrt) PCR CDVT SCR MBS 0 Unspecified drop>PCR
mark>SCR,MBS mark>SCR,MBS
ATM-UBR PCR CDVT - - 0 Unspecified drop>PCR ATM-UBR PCR CDVT - - 0 Unspecified drop>PCR
ATM-GFR.1 PCR CDVT MCR MBS 0 Unspecified drop>PCR ATM-GFR.1 PCR CDVT MCR MBS 0 Unspecified drop>PCR
ATM-GFR.2 PCR CDVT MCR MBS 0 Unspecified drop>PCR ATM-GFR.2 PCR CDVT MCR MBS 0 Unspecified drop>PCR
mark>MCR,MFS mark>MCR,MFS
Jamoussi, et. al. draft-ietf-mpls-cr-ldp-04.txt 35 Jamoussi, et. al. draft-ietf-mpls-crldp-06.txt 35
int-serv-CL p m r b 0 Frequent drop>p int-serv-CL p m r b 0 Frequent drop>p
drop>r,b drop>r,b
S= User specified S= User specified
In the above table, the DS refers to a delay sensitive service where In the above table, the DS refers to a delay sensitive service where
the network commits to deliver with high probability user datagrams the network commits to deliver with high probability user datagrams
at a rate of PDR with minimum delay and delay requirements. at a rate of PDR with minimum delay and delay requirements.
Datagrams in excess of PDR will be discarded. Datagrams in excess of PDR will be discarded.
skipping to change at line 1828 skipping to change at line 1827
the edge. The specification of those actions is expected to be a the edge. The specification of those actions is expected to be a
part of the service level agreement (SLA) negotiation and is not part of the service level agreement (SLA) negotiation and is not
included in the signaling protocol. For DS service, the edge action included in the signaling protocol. For DS service, the edge action
is to drop packets that exceed the PDR and the PBS specifications. is to drop packets that exceed the PDR and the PBS specifications.
The signaling message will be sent in the direction of the ER path The signaling message will be sent in the direction of the ER path
and the LSP is established following the normal LDP procedures. Each and the LSP is established following the normal LDP procedures. Each
LSR applies its admission control rules. If sufficient resources are LSR applies its admission control rules. If sufficient resources are
not available and the parameter values are subject to negotiation, not available and the parameter values are subject to negotiation,
then the LSR could negotiate down the PDR, the PBS, or both. then the LSR could negotiate down the PDR, the PBS, or both.
Jamoussi, et. al. draft-ietf-mpls-cr-ldp-04.txt 36 Jamoussi, et. al. draft-ietf-mpls-crldp-06.txt 36
The new parameter values are echoed back in the Label Mapping The new parameter values are echoed back in the Label Mapping
Message. LSRs might need to re-adjust their resource reservations Message. LSRs might need to re-adjust their resource reservations
based on the new traffic parameter values. based on the new traffic parameter values.
B.3 Establishing CR-LSP Supporting Delay Insensitive Applications B.3 Establishing CR-LSP Supporting Delay Insensitive Applications
In this example we assume that a throughput sensitive (TS) service In this example we assume that a throughput sensitive (TS) service
is requested. For resource allocation the user assigns values for is requested. For resource allocation the user assigns values for
PDR, PBS, CDR, and CBS. The negotiation flag is set if the traffic PDR, PBS, CDR, and CBS. The negotiation flag is set if the traffic
parameters are subject to negotiation. parameters are subject to negotiation.
skipping to change at line 1858 skipping to change at line 1857
high discard precedence values for all packets that exceed CDR and high discard precedence values for all packets that exceed CDR and
the CBS. The edge rules will also include dropping of packets that the CBS. The edge rules will also include dropping of packets that
conform to neither PDR nor PBS. conform to neither PDR nor PBS.
Each LSR of the LSP is expected to run its admission control rules Each LSR of the LSP is expected to run its admission control rules
and negotiate traffic parameters down if sufficient resources do not and negotiate traffic parameters down if sufficient resources do not
exist. The new parameter values are echoed back in the Label Mapping exist. The new parameter values are echoed back in the Label Mapping
Message. LSRs might need to re-adjust their resources based on the Message. LSRs might need to re-adjust their resources based on the
new traffic parameter values. new traffic parameter values.
Jamoussi, et. al. draft-ietf-mpls-cr-ldp-04.txt 37 Jamoussi, et. al. draft-ietf-mpls-crldp-06.txt 37
Full Copyright Statement Full Copyright Statement
"Copyright Ę The Internet Society (date). All Rights Reserved. This "Copyright The Internet Society (date). All Rights Reserved. This
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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 kind, provided that the above copyright notice and this paragraph
are included on all such copies and derivative works. However, this are 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
developing Internet standards in which case the procedures for developing Internet standards in which case the procedures for
copyrights defined in the Internet Standards process must be copyrights defined in the Internet Standards process must be
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English. English.
The limited permissions granted above are perpetual and will not be The limited permissions granted above are perpetual and will not be
revoked by the Internet Society or its successors or assigns. revoked by the Internet Society or its successors or assigns.
Jamoussi, et. al. draft-ietf-mpls-cr-ldp-04.txt 38 Jamoussi, et. al. draft-ietf-mpls-crldp-06.txt 38
 End of changes. 

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