draft-ietf-pce-disco-proto-isis-08.txt   rfc5089.txt 
Network Working Group J.L. Le Roux (Editor) Network Working Group JL. Le Roux, Ed.
Internet Draft France Telecom Request for Comments: 5089 France Telecom
Intended Status: Standard Track Category: Standards Track JP. Vasseur, Ed.
Expires: April 2008 J.P. Vasseur (Editor)
Cisco System Inc. Cisco System Inc.
Y. Ikejiri
Yuichi Ikejiri
NTT Communications NTT Communications
R. Zhang
BT
January 2008
Raymond Zhang IS-IS Protocol Extensions for
BT Infonet Path Computation Element (PCE) Discovery
October 2007
IS-IS Protocol Extensions for Path Computation Element (PCE) Discovery
draft-ietf-pce-disco-proto-isis-08.txt
Status of this Memo
By submitting this Internet-Draft, each author represents that any
applicable patent or other IPR claims of which he or she is aware
have been or will be disclosed, and any of which he or she becomes
aware will be disclosed, in accordance with Section 6 of BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF), its areas, and its working groups. Note that
other groups may also distribute working documents as Internet-
Drafts.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
The list of current Internet-Drafts can be accessed at
http://www.ietf.org/ietf/1id-abstracts.txt.
The list of Internet-Draft Shadow Directories can be accessed at
http://www.ietf.org/shadow.html.
Copyright Notice Status of This Memo
Copyright (C) The IETF Trust (2007). All rights reserved. This document specifies an Internet standards track protocol for the
Internet community, and requests discussion and suggestions for
improvements. Please refer to the current edition of the "Internet
Official Protocol Standards" (STD 1) for the standardization state
and status of this protocol. Distribution of this memo is unlimited.
Abstract Abstract
There are various circumstances where it is highly desirable for a There are various circumstances where it is highly desirable for a
Path Computation Client (PCC) to be able to dynamically and Path Computation Client (PCC) to be able to dynamically and
automatically discover a set of Path Computation Elements (PCEs), automatically discover a set of Path Computation Elements (PCEs),
along with information that can be used by the PCC for PCE selection. along with information that can be used by the PCC for PCE selection.
When the PCE is a Label Switching Router (LSR) participating in the When the PCE is a Label Switching Router (LSR) participating in the
Interior Gateway Protocol (IGP), or even a server participating Interior Gateway Protocol (IGP), or even a server participating
passively in the IGP, a simple and efficient way to announce PCEs passively in the IGP, a simple and efficient way to announce PCEs
consists of using IGP flooding. For that purpose this document consists of using IGP flooding. For that purpose, this document
defines extensions to the Intermediate System to Intermediate System defines extensions to the Intermediate System to Intermediate System
(IS-IS) routing protocol for the advertisement of PCE Discovery (IS-IS) routing protocol for the advertisement of PCE Discovery
information within an IS-IS area or within the entire IS-IS routing information within an IS-IS area or within the entire IS-IS routing
domain. domain.
Conventions used in this document
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 [RFC2119].
Table of Contents Table of Contents
1. Terminology.................................................3 1. Introduction ....................................................2
2. Introduction................................................4 2. Terminology .....................................................4
3. Overview....................................................5 3. Overview ........................................................5
3.1. PCE Discovery Information...................................5 3.1. PCE Discovery Information ..................................5
3.2. Flooding Scope..............................................5 3.2. Flooding Scope .............................................5
4. The IS-IS PCED Sub-TLV......................................6 4. The IS-IS PCED Sub-TLV ..........................................5
4.1. PCE-ADDRESS Sub-TLV.........................................7 4.1. PCE-ADDRESS Sub-TLV ........................................6
4.2. The PATH-SCOPE Sub-TLV......................................7 4.2. The PATH-SCOPE Sub-TLV .....................................7
4.3. PCE-DOMAIN Sub-TLV..........................................9 4.3. PCE-DOMAIN Sub-TLV .........................................9
4.4. NEIG-PCE-DOMAIN Sub-TLV....................................10 4.4. NEIG-PCE-DOMAIN Sub-TLV ...................................10
4.5. PCE-CAP-FLAGS Sub-TLV......................................10 4.5. PCE-CAP-FLAGS Sub-TLV .....................................10
5. Elements of Procedure......................................11 5. Elements of Procedure ..........................................11
6. Backward Compatibility.....................................12 6. Backward Compatibility .........................................12
7. IANA Considerations........................................12 7. IANA Considerations ............................................12
8. Security Considerations....................................12 8. Security Considerations ........................................12
9. Manageability Considerations...............................12 9. Manageability Considerations ...................................13
9.1. Control of Policy and Functions............................12 9.1. Control of Policy and Functions ...........................13
9.2. Information and Data Model.................................13 9.2. Information and Data Model ................................13
9.3. Liveness Detection and Monitoring..........................13 9.3. Liveness Detection and Monitoring .........................13
9.4. Verify Correct Operations..................................13 9.4. Verify Correct Operations .................................13
9.5. Requirements on Other Protocols and Functional 9.5. Requirements on Other Protocols and Functional
Components...............................................13 Components ................................................13
9.6. Impact on Network Operations...............................13 9.6. Impact on Network Operations ..............................14
10. Acknowledgments............................................14 10. Acknowledgments ...............................................14
11. References.................................................14 11. References ....................................................15
11.1. Normative References.......................................14 11.1. Normative References .....................................15
11.2. Informative References.....................................14 11.2. Informative References ...................................15
12. Editors' Addresses:........................................15
13. Contributors' Adresses:....................................15
14. Intellectual Property Statement............................15
1. Terminology
ABR: IS-IS Area Border Router.
AS: Autonomous System.
IGP: Interior Gateway Protocol. Either of the two routing
protocols Open Shortest Path First (OSPF) or Intermediate System
to Intermediate system (IS-IS).
Intra-area TE LSP: A TE LSP whose path does not cross an IGP area
boundary.
Intra-AS TE LSP: A TE LSP whose path does not cross an AS
boundary.
Inter-area TE LSP: A TE LSP whose path transits two or
more IGP areas. That is a TE LSP that crosses at least one IGP
area boundary.
Inter-AS TE LSP: A TE LSP whose path transits two or more
ASes or sub-ASes (BGP confederations). That is a TE LSP that
crosses at least one AS boundary.
IS-IS LSP: Link State PDU
LSR: Label Switching Router.
PCC: Path Computation Client. Any client application requesting a
path computation to be performed by a Path Computation Element.
PCE: Path Computation Element. An entity (component, application,
or network node) that is capable of computing a network path or
route based on a network graph, and applying computational
constraints.
PCE-Domain: In a PCE context this refers to any collection of
network elements within a common sphere of address management or
path computational responsibility (referred to as a "domain" in
[RFC4655]). Examples of PCE-Domains include IGP areas and ASes.
This should be distinguished from an IS-IS routing domain as
defined by [ISO].
PCEP: Path Computation Element communication Protocol.
TE LSP: Traffic Engineered Label Switched Path.
2. Introduction 1. Introduction
[RFC4655] describes the motivations and architecture for a Path [RFC4655] describes the motivations and architecture for a Path
Computation Element (PCE)-based path computation model for Multi- Computation Element (PCE)-based path computation model for
Protocol Label Switching (MPLS) and Generalized MPLS (GMPLS) Traffic Multi-Protocol Label Switching (MPLS) and Generalized MPLS (GMPLS)
Engineered Label Switched Paths (TE LSPs). The model allows for the Traffic Engineered Label Switched Paths (TE LSPs). The model allows
separation of the PCE from a Path Computation Client (PCC) (also for the separation of the PCE from a Path Computation Client (PCC)
referred to as a non co-located PCE) and allows for cooperation (also referred to as a non co-located PCE) and allows for cooperation
between PCEs (where one PCE acts as a PCC to make requests of the between PCEs (where one PCE acts as a PCC to make requests of the
other PCE). This relies on a communication protocol between PCC and other PCE). This relies on a communication protocol between a PCC
PCE, and also between PCEs. The requirements for such a communication and PCE, and also between PCEs. The requirements for such a
protocol can be found in [RFC4657], and the communication protocol is communication protocol can be found in [RFC4657], and the
defined in [PCEP]. communication protocol is defined in [PCEP].
The PCE architecture requires that a PCC be aware of the location of The PCE architecture requires that a PCC be aware of the location of
one or more PCEs in its domain, and also, potentially, of PCEs in one or more PCEs in its domain, and, potentially, of PCEs in other
other domains, e.g., in the case of inter-domain TE LSP computation. domains, e.g., in the case of inter-domain TE LSP computation.
A network may contain a large number of PCEs, each with potentially A network may contain a large number of PCEs, each with potentially
distinct capabilities. In such a context it is highly desirable to distinct capabilities. In such a context, it is highly desirable to
have a mechanism for automatic and dynamic PCE discovery that allows have a mechanism for automatic and dynamic PCE discovery that allows
PCCs to automatically discover a set of PCEs along with additional PCCs to automatically discover a set of PCEs, along with additional
information about each PCE that may be used by a PCC to perform PCE information about each PCE that may be used by a PCC to perform PCE
selection. Additionally, it is valuable for a PCC to dynamically selection. Additionally, it is valuable for a PCC to dynamically
detect new PCEs, failed PCEs, or any modification to the PCE detect new PCEs, failed PCEs, or any modification to the PCE
information. Detailed requirements for such a PCE discovery mechanism information. Detailed requirements for such a PCE discovery
are provided in [RFC4674]. mechanism are provided in [RFC4674].
Note that the PCE selection algorithm applied by a PCC is out of the Note that the PCE selection algorithm applied by a PCC is out of the
scope of this document. scope of this document.
When PCCs are LSRs participating in the IGP (OSPF, IS-IS), and PCEs When PCCs are LSRs participating in the IGP (OSPF or IS-IS), and PCEs
are either LSRs or servers also participating in the IGP, an are either LSRs or servers also participating in the IGP, an
effective mechanism for PCE discovery within an IGP routing domain effective mechanism for PCE discovery within an IGP routing domain
consists of utilizing IGP advertisements. consists of utilizing IGP advertisements.
This document defines extensions to IS-IS [ISO] to allow a PCE in an This document defines extensions to IS-IS [ISO] to allow a PCE in an
IS-IS routing domain to advertise its location along with some IS-IS routing domain to advertise its location, along with some
information useful to a PCC for PCE selection, so as to satisfy information useful to a PCC for PCE selection, so as to satisfy
dynamic PCE discovery requirements set forth in [RFC4674]. dynamic PCE discovery requirements set forth in [RFC4674].
Generic capability advertisement mechanisms for IS-IS are defined in Generic capability advertisement mechanisms for IS-IS are defined in
[IS-IS-CAP]. These allow a router to advertise its capabilities [RFC4971]. These allow a router to advertise its capabilities within
within an IS-IS area or an entire IS-IS routing domain. This document an IS-IS area or an entire IS-IS routing domain. This document
leverages this generic capability advertisement mechanism to fully leverages this generic capability advertisement mechanism to fully
satisfy the dynamic PCE discovery requirements. satisfy the dynamic PCE discovery requirements.
This document defines a new sub-TLV (named the PCE Discovery (PCED)) This document defines a new sub-TLV (named the PCE Discovery (PCED))
to be carried within the IS-IS Router Capability TLV ([IS-IS-CAP]). to be carried within the IS-IS Router Capability TLV ([RFC4971]).
The PCE information advertised is detailed in Section 3. Protocol The PCE information advertised is detailed in Section 3. Protocol
extensions and procedures are defined in Sections 4 and 5. extensions and procedures are defined in Sections 4 and 5.
The IS-IS extensions defined in this document allow for PCE discovery The IS-IS extensions defined in this document allow for PCE discovery
within an IS-IS routing domain. Solutions for PCE discovery across AS within an IS-IS routing domain. Solutions for PCE discovery across
boundaries are beyond the scope of this document, and for further AS boundaries are beyond the scope of this document, and are for
study. further study.
This document defines a set of sub-TLVs that are nested within each This document defines a set of sub-TLVs that are nested within each
other. When the degree of nesting TLVs is 2 (a TLV is carried within other. When the degree of nesting TLVs is 2 (a TLV is carried within
another TLV) the TLV carried within a TLV is called a sub-TLV. another TLV) the TLV carried within a TLV is called a sub-TLV.
Strictly speaking, when the degree of nesting is 3, a subsub-TLV is Strictly speaking, when the degree of nesting is 3, a sub-sub-TLV is
carried within a sub-TLV that is itself carried within a TLV. For the carried within a sub-TLV that is itself carried within a TLV. For
sake of terminology simplicity, a TLV carried within another TLV is the sake of terminology simplicity, a TLV carried within another TLV
called a sub-TLV regardless of the degree of nesting. is called a sub-TLV regardless of the degree of nesting.
2. Terminology
ABR: IS-IS Area Border Router.
AS: Autonomous System.
IGP: Interior Gateway Protocol. Either of the two routing protocols,
Open Shortest Path First (OSPF) or Intermediate System to
Intermediate system (IS-IS).
Intra-area TE LSP: A TE LSP whose path does not cross an IGP area
boundary.
Intra-AS TE LSP: A TE LSP whose path does not cross an AS boundary.
Inter-area TE LSP: A TE LSP whose path transits two or more IGP
areas. That is, a TE LSP that crosses at least one IGP area
boundary.
Inter-AS TE LSP: A TE LSP whose path transits two or more ASes or
sub-ASes (BGP confederations). That is, a TE LSP that crosses at
least one AS boundary.
IS-IS LSP: Link State PDU.
LSR: Label Switching Router.
PCC: Path Computation Client. Any client application requesting a
path computation to be performed by a Path Computation Element.
PCE: Path Computation Element. An entity (component, application, or
network node) that is capable of computing a network path or route
based on a network graph and applying computational constraints.
PCED: PCE Discovery.
PCE-Domain: In a PCE context, this refers to any collection of
network elements within a common sphere of address management or path
computational responsibility (referred to as a "domain" in
[RFC4655]). Examples of PCE-Domains include IGP areas and ASes.
This should be distinguished from an IS-IS routing domain as defined
by [ISO].
PCEP: Path Computation Element communication Protocol.
TE LSP: Traffic Engineered Label Switched Path.
TLV: Type-Length-Variable data encoding.
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 [RFC2119].
3. Overview 3. Overview
3.1. PCE Discovery Information 3.1. PCE Discovery Information
The PCE discovery information is composed of: The PCE discovery information is composed of:
- The PCE location: an IPv4 and/or IPv6 address that is used to reach - The PCE location: an IPv4 and/or IPv6 address that is used to
the PCE. It is RECOMMENDED to use an address that is always reach the PCE. It is RECOMMENDED to use an address that is always
reachable if there is any connectivity to the PCE; reachable if there is any connectivity to the PCE;
- The PCE path computation scope (i.e., intra-layer, inter-area, - The PCE path computation scope (i.e., intra-layer, inter-area,
inter-AS, or inter-layer); inter-AS, or inter-layer);
- The set of one or more PCE-Domain(s) into which the PCE has - The set of one or more PCE-Domain(s) into which the PCE has
visibility and for which the PCE can compute paths; visibility and for which the PCE can compute paths;
- The set of zero, one or more neighbor PCE-Domain(s) toward which - The set of zero, one, or more neighbor PCE-Domain(s) toward which
the PCE can compute paths; the PCE can compute paths;
- A set of communication capabilities (e.g., support for request - A set of communication capabilities (e.g., support for request
prioritization) and path computation-specific capabilities prioritization) and path computation-specific capabilities (e.g.,
(e.g., supported constraints). supported constraints).
PCE discovery information is by nature fairly static and does not PCE discovery information is, by nature, fairly static and does not
change with PCE activity. Changes in PCE discovery information may change with PCE activity. Changes in PCE discovery information may
occur as a result of PCE configuration updates, PCE occur as a result of PCE configuration updates, PCE
deployment/activation, PCE deactivation/suppression, or PCE failure. deployment/activation, PCE deactivation/suppression, or PCE failure.
Hence, this information is not expected to change frequently. Hence, this information is not expected to change frequently.
3.2. Flooding Scope 3.2. Flooding Scope
The flooding scope for PCE information advertised through IS-IS can The flooding scope for PCE information advertised through IS-IS can
be a single L1 area, an L1 area and the L2 sub-domain, or the entire be a single L1 area, an L1 area and the L2 sub-domain, or the entire
IS-IS routing domain. IS-IS routing domain.
skipping to change at page 6, line 17 skipping to change at page 6, line 7
The IS-IS PCED sub-TLV contains a non-ordered set of sub-TLVs. The IS-IS PCED sub-TLV contains a non-ordered set of sub-TLVs.
The format of the IS-IS PCED sub-TLV and its sub-TLVs is identical to The format of the IS-IS PCED sub-TLV and its sub-TLVs is identical to
the TLV format used by the Traffic Engineering Extensions to IS-IS the TLV format used by the Traffic Engineering Extensions to IS-IS
[RFC3784]. That is, the TLV is comprised of 1 octet for the type, 1 [RFC3784]. That is, the TLV is comprised of 1 octet for the type, 1
octet specifying the TLV length, and a value field. The Length field octet specifying the TLV length, and a value field. The Length field
defines the length of the value portion in octets. defines the length of the value portion in octets.
The IS-IS PCED sub-TLV has the following format: The IS-IS PCED sub-TLV has the following format:
TYPE: To be assigned by IANA (suggested value = 5) TYPE: 5
LENGTH: Variable LENGTH: Variable
VALUE: set of sub-TLVs VALUE: Set of sub-TLVs
Five sub-TLVs are defined: Five sub-TLVs are defined:
Sub-TLV type Length Name Sub-TLV type Length Name
1 variable PCE-ADDRESS sub-TLV 1 variable PCE-ADDRESS sub-TLV
2 3 PATH-SCOPE sub-TLV 2 3 PATH-SCOPE sub-TLV
3 variable PCE-DOMAIN sub-TLV 3 variable PCE-DOMAIN sub-TLV
4 variable NEIG-PCE-DOMAIN sub-TLV 4 variable NEIG-PCE-DOMAIN sub-TLV
5 variable PCE-CAP-FLAGS sub-TLV 5 variable PCE-CAP-FLAGS sub-TLV
The PCE-ADDRESS and PATH-SCOPE sub-TLVs MUST always be present within The PCE-ADDRESS and PATH-SCOPE sub-TLVs MUST always be present within
the PCED sub-TLV. the PCED sub-TLV.
skipping to change at page 6, line 32 skipping to change at page 6, line 23
Sub-TLV type Length Name Sub-TLV type Length Name
1 variable PCE-ADDRESS sub-TLV 1 variable PCE-ADDRESS sub-TLV
2 3 PATH-SCOPE sub-TLV 2 3 PATH-SCOPE sub-TLV
3 variable PCE-DOMAIN sub-TLV 3 variable PCE-DOMAIN sub-TLV
4 variable NEIG-PCE-DOMAIN sub-TLV 4 variable NEIG-PCE-DOMAIN sub-TLV
5 variable PCE-CAP-FLAGS sub-TLV 5 variable PCE-CAP-FLAGS sub-TLV
The PCE-ADDRESS and PATH-SCOPE sub-TLVs MUST always be present within The PCE-ADDRESS and PATH-SCOPE sub-TLVs MUST always be present within
the PCED sub-TLV. the PCED sub-TLV.
The PCE-DOMAIN and NEIG-PCE-DOMAIN sub-TLVs are optional. They The PCE-DOMAIN and NEIG-PCE-DOMAIN sub-TLVs are optional. They MAY
MAY be present in the PCED sub-TLV to facilitate selection of inter- be present in the PCED sub-TLV to facilitate selection of
domain PCEs. inter-domain PCEs.
The PCE-CAP-FLAGS sub-TLV is optional and MAY be present in the PCED The PCE-CAP-FLAGS sub-TLV is optional and MAY be present in the PCED
sub-TLV to facilitate the PCE selection process. sub-TLV to facilitate the PCE selection process.
Any unrecognized sub-TLV MUST be silently ignored. Any unrecognized sub-TLV MUST be silently ignored.
The PCED sub-TLV is carried within an IS-IS CAPABILITY TLV defined in The PCED sub-TLV is carried within an IS-IS CAPABILITY TLV defined in
[IS-IS-CAP]. [RFC4971].
No additional sub-TLVs will be added to the PCED TLV in the future. No additional sub-TLVs will be added to the PCED TLV in the future.
If a future application requires the advertisement of additional PCE If a future application requires the advertisement of additional PCE
information in IS-IS, this will not be carried in the CAPABILITY TLV. information in IS-IS, this will not be carried in the CAPABILITY TLV.
The following sub-sections describe the sub-TLVs which may be carried The following sub-sections describe the sub-TLVs that may be carried
within the PCED sub-TLV. within the PCED sub-TLV.
4.1. PCE-ADDRESS Sub-TLV 4.1. PCE-ADDRESS Sub-TLV
The PCE-ADDRESS sub-TLV specifies an IP address that can be The PCE-ADDRESS sub-TLV specifies an IP address that can be used to
used to reach the PCE. It is RECOMMENDED to make use of an address reach the PCE. It is RECOMMENDED to make use of an address that is
that is always reachable, provided the PCE is alive and reachable. always reachable, provided the PCE is alive and reachable.
The PCE-ADDRESS sub-TLV is mandatory; it MUST be present within the The PCE-ADDRESS sub-TLV is mandatory; it MUST be present within the
PCED sub-TLV. It MAY appear twice, when the PCE has both an IPv4 and PCED sub-TLV. It MAY appear twice, when the PCE has both an IPv4 and
IPv6 address. It MUST NOT appear more than once for the same address IPv6 address. It MUST NOT appear more than once for the same address
type. If it appears more than once only the first occurrence is type. If it appears more than once for the same address type, only
processed and any others MUST be ignored. the first occurrence is processed and any others MUST be ignored.
The PCE-ADDRESS sub-TLV has the following format: The PCE-ADDRESS sub-TLV has the following format:
TYPE: 1 TYPE: 1
LENGTH: 5 for an IPv4 address or 17 for an IPv6 address LENGTH: 5 for an IPv4 address or 17 for an IPv6 address.
VALUE: This comprises one octet indicating the address-type and 4 VALUE: This comprises one octet indicating the address-type and 4
or 16 octets encoding the IPv4 or IPv6 address to be used or 16 octets encoding the IPv4 or IPv6 address to be used
to reach the PCE. to reach the PCE.
Address-type: Address-type:
1 IPv4 1 IPv4
2 IPv6 2 IPv6
4.2. The PATH-SCOPE Sub-TLV 4.2. The PATH-SCOPE Sub-TLV
The PATH-SCOPE sub-TLV indicates the PCE path computation scope, The PATH-SCOPE sub-TLV indicates the PCE path computation scope,
which refers to the PCE's ability to compute or take part in the which refers to the PCE's ability to compute or take part in the
computation of paths for intra-area, inter-area, inter-AS, or inter- computation of paths for intra-area, inter-area, inter-AS, or
layer_TE LSPs. inter-layer TE LSPs.
The PATH-SCOPE sub-TLV is mandatory; it MUST be present within the The PATH-SCOPE sub-TLV is mandatory; it MUST be present within the
PCED sub-TLV. There MUST be exactly one instance of the PATH-SCOPE PCED sub-TLV. There MUST be exactly one instance of the PATH-SCOPE
sub-TLV within each PCED sub-TLV. If it appears more than once only sub-TLV within each PCED sub-TLV. If it appears more than once only
the first occurrence is processed and any others MUST be ignored. the first occurrence is processed and any others MUST be ignored.
The PATH-SCOPE sub-TLV contains a set of bit flags indicating the The PATH-SCOPE sub-TLV contains a set of bit flags indicating the
supported path scopes, and four fields indicating PCE preferences. supported path scopes, and four fields indicating PCE preferences.
The PATH-SCOPE sub-TLV has the following format: The PATH-SCOPE sub-TLV has the following format:
TYPE: 2 TYPE: 2
LENGTH: 3 LENGTH: 3
VALUE: This comprises a one-octet flags field where each flag VALUE: This comprises a 1-octet flags field where each flag
represents a supported path scope, followed by a 2-octets represents a supported path scope, followed by a 2-octet
preferences field indicating PCE preferences. preferences field indicating PCE preferences.
Here is the structure of the flags field: Here is the structure of the flags field:
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
|0|1|2|3|4|5|Res| |0|1|2|3|4|5|Res|
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
Bit Path Scope Bit Path Scope
0 L bit: Can compute intra-area path 0 L bit: Can compute intra-area paths.
1 R bit: Can act as PCE for inter-area TE LSP computation 1 R bit: Can act as PCE for inter-area TE LSP computation.
2 Rd bit: Can act as a default PCE for inter-area TE LSP 2 Rd bit: Can act as a default PCE for inter-area TE LSP
computation computation.
3 S bit: Can act as PCE for inter-AS TE LSP computation 3 S bit: Can act as PCE for inter-AS TE LSP computation.
4 Sd bit: Can act as a default PCE for inter-AS TE LSPs 4 Sd bit: Can act as a default PCE for inter-AS TE LSP
computation computation.
5 Y bit: Can compute or take part into the computation of 5 Y bit: Can act as PCE for inter-layer TE LSP
paths across layers computation.
6-7 Reserved for future use. 6-7 Reserved for future use.
Here is the structure of the preferences field Here is the structure of the preferences field:
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|PrefL|PrefR|PrefS|PrefY| Res | |PrefL|PrefR|PrefS|PrefY| Res |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Res: Reserved for future usage. PrefL field: PCE's preference for intra-area TE LSP computation.
PrefL field: PCE's preference for intra-area TE LSPs computation.
PrefR field: PCE's preference for inter-area TE LSPs computation. PrefR field: PCE's preference for inter-area TE LSP computation.
PrefS field: PCE's preference for inter-AS TE LSPs computation. PrefS field: PCE's preference for inter-AS TE LSP computation.
Pref-Y field: PCE's preference for inter-layer TE LSPs computation. Pref-Y field: PCE's preference for inter-layer TE LSP computation.
Res: Reserved for future use. Res: Reserved for future use.
The L, R, S, and Y bits are set when the PCE can act as a PCE for The L, R, S, and Y bits are set when the PCE can act as a PCE for
intra-area, inter-area, inter-AS or inter-layer TE LSPs computation intra-area, inter-area, inter-AS, or inter-layer TE LSP computation,
respectively. These bits are non-exclusive. respectively. These bits are non-exclusive.
When set, the Rd bit indicates that the PCE can act as a default PCE When set, the Rd bit indicates that the PCE can act as a default PCE
for inter-area TE LSP computation (that is, the PCE can compute a for inter-area TE LSP computation (that is, the PCE can compute a
path toward any neighbor area). Similarly, when set, the Sd bit path toward any neighbor area). Similarly, when set, the Sd bit
indicates that the PCE can act as a default PCE for inter-AS TE LSP indicates that the PCE can act as a default PCE for inter-AS TE LSP
computation (the PCE can compute a path toward any neighbor AS). computation (the PCE can compute a path toward any neighbor AS).
When the Rd and Sd bit are set, the PCED sub-TLV MUST NOT contain a When the Rd and Sd bit are set, the PCED sub-TLV MUST NOT contain a
NEIG-PCE-DOMAIN sub-TLV (see Section 4.4). NEIG-PCE-DOMAIN sub-TLV (see Section 4.4).
When the R bit is clear, the Rd bit SHOULD be clear on transmission When the R bit is clear, the Rd bit SHOULD be clear on transmission
and MUST be ignored on receipt. When the S bit is clear, the Sd bit and MUST be ignored on receipt. When the S bit is clear, the Sd bit
SHOULD be clear on transmission and MUST be ignored on receipt. SHOULD be clear on transmission and MUST be ignored on receipt.
The PrefL, PrefR, PrefS and PrefY fields are each three bits long and The PrefL, PrefR, PrefS and PrefY fields are each three bits long and
allow the PCE to specify a preference for each computation scope, allow the PCE to specify a preference for each computation scope,
where 7 reflects the highest preference. Such preferences can be used where 7 reflects the highest preference. Such preferences can be
for weighted load balancing of path computation requests. An operator used for weighted load balancing of path computation requests. An
may decide to configure a preference for each computation scope at operator may decide to configure a preference for each computation
each PCE so as to balance the path computation load among them. The scope at each PCE so as to balance the path computation load among
algorithms used by a PCC to balance its path computation requests them. The algorithms used by a PCC to balance its path computation
according to such PCE preferences are out of the scope of this requests according to such PCE preferences are out of the scope of
document and are a matter for local or network-wide policy. The same this document and are a matter for local or network-wide policy. The
or different preferences may be used for each scope. For instance, an same or different preferences may be used for each scope. For
operator that wants a PCE capable of both inter-area and inter-AS instance, an operator that wants a PCE capable of both inter-area and
computation to be preferred for use for inter-AS computations may inter-AS computation to be preferred for use for inter-AS
configure PrefS higher than PrefR. computations may configure PrefS higher than PrefR.
When the L, R, S, or Y bits are clear, the PrefL, PrefR, PrefS, PrefY When the L, R, S, or Y bits are cleared, the PrefL, PrefR, PrefS, and
fields SHOULD respectively be set to 0 on transmission and MUST be PrefY fields SHOULD respectively be set to 0 on transmission and MUST
ignored on receipt. be ignored on receipt.
Both reserved fields SHOULD be set to zero on transmission and MUST Both reserved fields SHOULD be set to zero on transmission and MUST
be ignored on receipt. be ignored on receipt.
4.3. PCE-DOMAIN Sub-TLV 4.3. PCE-DOMAIN Sub-TLV
The PCE-DOMAIN sub-TLV specifies a PCE-Domain (areas and/or ASes) The PCE-DOMAIN sub-TLV specifies a PCE-Domain (area and/or AS) where
where the PCE has topology visibility and through which the PCE can the PCE has topology visibility and through which the PCE can compute
compute paths. paths.
The PCE-DOMAIN sub-TLV SHOULD be present when PCE-Domains for which The PCE-DOMAIN sub-TLV SHOULD be present when PCE-Domains for which
the PCE can operate cannot be inferred by other IGP information, for the PCE can operate cannot be inferred by other IGP information: for
instance when the PCE is inter-domain capable (i.e., when the R bit instance, when the PCE is inter-domain capable (i.e., when the R bit
or S bit is set) and the flooding scope is the entire routing domain or S bit is set) and the flooding scope is the entire routing domain
(see Section 5 for a discussion of how the flooding scope is set and (see Section 5 for a discussion of how the flooding scope is set and
interpreted). interpreted).
A PCED sub-TLV may include multiple PCE-DOMAIN sub-TLVs when the PCE A PCED sub-TLV may include multiple PCE-DOMAIN sub-TLVs when the PCE
has visibility into multiple PCE-Domains. has visibility into multiple PCE-Domains.
The PCE-DOMAIN sub-TLV has the following format: The PCE-DOMAIN sub-TLV has the following format:
TYPE: 3 TYPE: 3
LENGTH: Variable LENGTH: Variable
VALUE: This is composed of one octet indicating the domain-type (area VALUE: This is composed of one octet indicating the domain-type
ID or AS Number) and a variable length IS-IS area ID or a 32 bits AS (area ID or AS Number) and a variable length IS-IS area ID
number, identifying a PCE-domain where the PCE has visibility and can or a 32-bit AS number, identifying a PCE-Domain where the
compute paths. PCE has visibility and can compute paths.
Two domain types are defined: Two domain types are defined:
1 Area ID 1 Area ID
2 AS Number 2 AS Number
The Area ID is the area address as defined in [ISO]. The Area ID is the area address as defined in [ISO].
When the AS number is coded in two octets, the AS Number field MUST When the AS number is coded in two octets, the AS Number field MUST
have its first two octets set to 0. have its first two octets set to 0.
4.4. NEIG-PCE-DOMAIN Sub-TLV 4.4. NEIG-PCE-DOMAIN Sub-TLV
The NEIG-PCE-DOMAIN sub-TLV specifies a neighbor PCE-domain (area or The NEIG-PCE-DOMAIN sub-TLV specifies a neighbor PCE-Domain (area or
AS) toward which a PCE can compute paths. It means that the PCE can AS) toward which a PCE can compute paths. It means that the PCE can
take part in the computation of inter-domain TE LSPs with paths that take part in the computation of inter-domain TE LSPs with paths that
transit this neighbor PCE-domain. transit this neighbor PCE-Domain.
A PCED sub-TLV may include several NEIG-PCE-DOMAIN sub-TLVs when the A PCED sub-TLV may include several NEIG-PCE-DOMAIN sub-TLVs when the
PCE can compute paths towards several neighbour PCE-domains. PCE can compute paths towards several neighbor PCE-Domains.
The NEIG-PCE-DOMAIN sub-TLV has the same format as the PCE-DOMAIN The NEIG-PCE-DOMAIN sub-TLV has the same format as the PCE-DOMAIN
sub-TLV: sub-TLV:
TYPE: 4 TYPE: 4
LENGTH: Variable LENGTH: Variable
VALUE: This comprises one octet indicating the domain-type (area ID VALUE: This comprises one octet indicating the domain-type (area
or AS Number) and a variable length IS-IS area ID or a 32 bits AS ID or AS Number) and a variable length IS-IS area ID or a
number, identifying a PCE-domain toward which the PCE can compute 32-bit AS number, identifying a PCE-Domain toward which
paths. the PCE can compute paths.
Two domain types are defined: Two domain types are defined:
1 Area ID 1 Area ID
2 AS Number 2 AS Number
The Area ID is the area address as defined in [ISO]. The Area ID is the area address as defined in [ISO].
When the AS number is coded in two octets, the AS Number field MUST When the AS number is coded in two octets, the AS Number field MUST
have its first two octets set to 0. have its first two octets set to 0.
The NEIG-PCE-DOMAIN sub-TLV MUST be present at least once with domain The NEIG-PCE-DOMAIN sub-TLV MUST be present at least once with
type 1 if the R bit is set and the Rd bit is clear, and MUST be domain-type set to 1 if the R bit is set and the Rd bit is cleared,
present at least once with domain type 2 if the S bit is set and the and MUST be present at least once with domain-type set to 2 if the S
Sd bit is clear. bit is set and the Sd bit is cleared.
4.5. PCE-CAP-FLAGS Sub-TLV 4.5. PCE-CAP-FLAGS Sub-TLV
The PCE-CAP-FLAGs sub-TLV is an optional sub-TLV used to indicate The PCE-CAP-FLAGS sub-TLV is an optional sub-TLV used to indicate PCE
PCEP related capabilities. It MAY be present within the PCED sub-TLV. capabilities. It MAY be present within the PCED sub-TLV. It MUST
It MUST NOT be present more than once. If it appears more than once NOT be present more than once. If it appears more than once, only
only the first occurrence is processed and any others MUST be ignored. the first occurrence is processed and any others MUST be ignored.
The value field of the PCE-CAP-FLAGS sub-TLV is made up of an array The value field of the PCE-CAP-FLAGS sub-TLV is made up of an array
of units of 32 bit-flags numbered from the most significant as bit of units of 32-bit flags numbered from the most significant bit as
zero, where each bit represents one PCE capability. bit zero, where each bit represents one PCE capability.
The PCE-CAP-FLAGS sub-TLV has the following format: The PCE-CAP-FLAGS sub-TLV has the following format:
TYPE: 5 TYPE: 5
LENGTH: Multiple of 4 LENGTH: Multiple of 4
VALUE: This contains an array of units of 32 bit flags numbered VALUE: This contains an array of units of 32-bit flags numbered
from the most significant as bit zero, where each bit from the most significant as bit zero, where each bit
represents one PCE capability. represents one PCE capability.
The PCE capability registry is managed by IANA, it is common The PCE capability registry is managed by IANA; it is common with
with OSPF and defined in [PCED-OSPF]. OSPF and defined in [RFC5088].
Reserved bits SHOULD be set to zero on transmission and MUST be Reserved bits SHOULD be set to zero on transmission and MUST be
ignored on receipt. ignored on receipt.
5. Elements of Procedure 5. Elements of Procedure
The PCED sub-TLV is advertised within an IS-IS Router Capability TLV The PCED sub-TLV is advertised within an IS-IS Router Capability TLV
defined in [IS-IS-CAP]. As such, elements of procedures are inherited defined in [RFC4971]. As such, elements of procedures are inherited
from those defined in [IS-IS-CAP]. from those defined in [RFC4971].
The flooding scope is controlled by the S flag in the IS-IS Router The flooding scope is controlled by the S flag in the IS-IS Router
Capability TLV (see [IS-IS-CAP]). When the scope of the PCED sub-TLV Capability TLV (see [RFC4971]). When the scope of the PCED sub-TLV
is area local it MUST be carried within an IS-IS Router Capability is area local, it MUST be carried within an IS-IS Router Capability
TLV having the S bit cleared. When the scope of the PCED sub-TLV is TLV having the S bit cleared. When the scope of the PCED sub-TLV is
the entire IS-IS routing domain, it MUST be carried within an IS-IS the entire IS-IS routing domain, it MUST be carried within an IS-IS
Router Capability TLV having the S bit set. Note that when only the L Router Capability TLV having the S bit set. Note that when only the
bit of the PATH-SCOPE sub-TLV is set, the flooding scope MUST be area L bit of the PATH-SCOPE sub-TLV is set, the flooding scope MUST be
local. area local.
Note that a L1L2 node may include a PCED TLV in a Router Capability Note that an L1L2 node may include a PCED TLV in a Router Capability
TLV with the S bit cleared in both in its L1 and L2 LSPs. This allows TLV with the S bit cleared in both in its L1 and L2 LSPs. This
the flooding scope to be restricted to the L1 area and the L2 sub- allows the flooding scope to be restricted to the L1 area and the L2
domain. sub-domain.
When the PCE function is deactivated, the IS-IS speaker advertising When the PCE function is deactivated, the IS-IS speaker advertising
this PCE MUST originate a new IS-IS LSP that no longer includes the this PCE MUST originate a new IS-IS LSP that no longer includes the
corresponding PCED TLV. corresponding PCED TLV.
The PCE address (i.e., the address indicated within the PCE ADDRESS The PCE address (i.e., the address indicated within the PCE-ADDRESS
sub-TLV) SHOULD be reachable via some prefixes advertised by IS-IS. sub-TLV) SHOULD be reachable via some prefixes advertised by IS-IS.
This allows the detection of a PCE failure to be sped up. When the
PCE address is no longer reachable, the PCE node has failed, has been The PCED sub-TLV information regarding a specific PCE is only
torn down, or there is no longer IP connectivity to the PCE node. considered current and useable when the router advertising this
information is itself reachable via IS-IS calculated paths at the
level of the LSP in which the PCED sub-TLV appears.
A change in the state of a PCE (activate, deactivate, parameter
change) MUST result in a corresponding change in the PCED sub-TLV
information advertised by an IS-IS router (inserted, removed,
updated) in its LSP. The way PCEs determine the information they
advertise, and how that information is made available to IS-IS, is
out of the scope of this document. Some information may be
configured (e.g., address, preferences, scope) and other information
may be automatically determined by the PCE (e.g., areas of
visibility).
A change in information in the PCED sub-TLV MUST NOT trigger any SPF A change in information in the PCED sub-TLV MUST NOT trigger any SPF
computation at a receiving router. computation at a receiving router.
The way PCEs determine the information they advertise is out of the
scope of this document. Some information may be configured (e.g.,
address, preferences, scope) and other information may be
automatically determined by the PCE (e.g. areas of visibility).
6. Backward Compatibility 6. Backward Compatibility
The PCED sub-TLV defined in this document does not introduce any The PCED sub-TLV defined in this document does not introduce any
interoperability issues. interoperability issues.
An IS-IS router not supporting the PCED sub-TLV will just silently An IS-IS router not supporting the PCED sub-TLV will just silently
ignore the sub-TLV as specified in [IS-IS-CAP]. ignore the sub-TLV as specified in [RFC4971].
7. IANA Considerations 7. IANA Considerations
IANA has defined a registry for the sub-TLVs carried in the IS-IS IANA has defined a registry for the sub-TLVs carried in the IS-IS
Router Capability sub-TLVs defined in [IS-IS-CAP]. IANA is requested Router Capability TLV defined in [RFC4971]. IANA has assigned a new
to assign a new sub-TLV code-point for the PCED sub-TLV carried sub-TLV codepoint for the PCED sub-TLV carried within the Router
within the Router Capability sub-TLV. Capability TLV.
Value Sub-TLV References Value Sub-TLV References
----- -------- ---------- ----- -------- ----------
5 PCED sub-TLV (this document) 5 PCED sub-TLV (this document)
8. Security Considerations 8. Security Considerations
This document defines IS-IS extensions for PCE discovery within an This document defines IS-IS extensions for PCE discovery within an
administrative domain. Hence the security of the PCE discovery relies administrative domain. Hence the security of the PCE discovery
on the security of IS-IS. relies on the security of IS-IS.
Mechanisms defined to ensure authenticity and integrity of IS-IS LSPs Mechanisms defined to ensure authenticity and integrity of IS-IS LSPs
[RFC3567], and their TLVs, can be used to secure the PCED sub-TLV as [RFC3567] and their TLVs, can be used to secure the PCED sub-TLV as
well. well.
IS-IS provides no encryption mechanism for protecting the privacy of IS-IS provides no encryption mechanism for protecting the privacy of
LSPs, and in particular the privacy of the PCE discovery information. LSPs and, in particular, the privacy of the PCE discovery
information.
9. Manageability Considerations 9. Manageability Considerations
Manageability considerations for PCE Discovery are addressed in Manageability considerations for PCE Discovery are addressed in
Section 4.10 of [RFC4674]. Section 4.10 of [RFC4674].
9.1. Control of Policy and Functions 9.1. Control of Policy and Functions
Requirements for the configuration of PCE discovery parameters on Requirements for the configuration of PCE discovery parameters on
PCCs and PCEs are discussed in Section 4.10.1 of [RFC4674]. PCCs and PCEs are discussed in Section 4.10.1 of [RFC4674].
In particular, a PCE implementation SHOULD allow the following In particular, a PCE implementation SHOULD allow the following
parameters to be configured on the PCE: parameters to be configured on the PCE:
-The PCE IPv4/IPv6 address(es) (see Section 4.1)
-The PCE Scope, including the inter-domain functions (inter- -The PCE IPv4/IPv6 address(es) (see Section 4.1).
area, inter-AS, inter-layer), the preferences, and whether the
PCE can act as default PCE (see Section 4.2) -The PCE Scope, including the inter-domain functions (inter-area,
-The PCE domains (see Section 4.3) inter-AS, inter-layer), the preferences, and whether the PCE can
-The neighbour PCE domains (see Section 4.4) act as default PCE (see Section 4.2).
-The PCE capabilities (see Section 4.5)
-The PCE-Domains (see Section 4.3).
-The neighbor PCE-Domains (see Section 4.4).
-The PCE capabilities (see Section 4.5).
9.2. Information and Data Model 9.2. Information and Data Model
A MIB module for PCE Discovery is defined in [PCED-MIB]. A MIB module for PCE Discovery is defined in [PCED-MIB].
9.3. Liveness Detection and Monitoring 9.3. Liveness Detection and Monitoring
PCE Discovery Protocol liveness detection relies upon IS-IS liveness This document specifies the use of IS-IS as a PCE Discovery Protocol.
detection. IS-IS already includes a liveness detection mechanism The requirements specified in [RFC4674] include the ability to
(Hello PDUs), and PCE discovery does not require additional determine liveness of the PCE Discovery protocol. Normal operation
capabilities. of the IS-IS protocol meets these requirements.
Procedures defined in Section 5 allow a PCC to detect when a PCE has
been deactivated, or is no longer reachable.
9.4. Verify Correct Operations 9.4. Verify Correct Operations
The correlation of information advertised against information The correlation of information advertised against information
received can be achieved by comparing the information in the PCED received can be achieved by comparing the information in the PCED
sub-TLV received by the PCC with that stored at the PCE using the sub-TLV received by the PCC with that stored at the PCE using the
PCED MIB [PCED-MIB]. The number of dropped, corrupt, and rejected PCED MIB [PCED-MIB]. The number of dropped, corrupt, and rejected
information elements are available through the PCED MIB. information elements are available through the PCED MIB.
9.5. Requirements on Other Protocols and Functional Components 9.5. Requirements on Other Protocols and Functional Components
The IS-IS extensions defined in this document do not imply any The IS-IS extensions defined in this document do not imply any
requirement on other protocols. requirements on other protocols.
9.6. Impact on Network Operations 9.6. Impact on Network Operations
Frequent changes in PCE information advertised in the PCED sub-TLV Frequent changes in PCE information advertised in the PCED sub-TLV
may have a significant impact on IS-IS and might destabilize the may have a significant impact on IS-IS and might destabilize the
operation of the network by causing the PCCs to swap between PCEs. operation of the network by causing the PCCs to swap between PCEs.
As discussed in Section 4.10.4 of [RFC4674], it MUST be possible to As discussed in Section 4.10.4 of [RFC4674], it MUST be possible to
apply at least the following controls: apply at least the following controls:
- Configurable limit on the rate of announcement of changed - Configurable limit on the rate of announcement of changed
parameters at a PCE. parameters at a PCE.
- Control of the impact on PCCs such as through rate-limiting the
processing of PCED sub-TLVs. - Control of the impact on PCCs, such as through rate-limiting
the processing of PCED sub-TLVs.
- Configurable control of triggers that cause a PCC to swap to - Configurable control of triggers that cause a PCC to swap to
another PCE. another PCE.
10. Acknowledgments 10. Acknowledgments
We would like to thank Lucy Wong, Adrian Farrel, Les Ginsberg, Mike We would like to thank Lucy Wong, Adrian Farrel, Les Ginsberg, Mike
Shand, Lou Berger, and David Ward, for their useful comments and Shand, Lou Berger, David Ward, Ross Callon, and Lisa Dusseault for
suggestions. their useful comments and suggestions.
11. References 11. References
11.1. Normative References 11.1. Normative References
[ISO] "Intermediate System to Intermediate System Intra-Domain
Routeing Exchange Protocol for use in Conjunction with
the Protocol for Providing the Connectionless-mode
Network Service" ISO/IEC 10589:2002 Second Edition.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997. Requirement Levels", BCP 14, RFC 2119, March 1997.
[ISO] "Intermediate System to Intermediate System Intra-Domain [RFC3567] Li, T. and R. Atkinson, "Intermediate System to
Routeing Exchange Protocol for use in Conjunction with the Intermediate System (IS-IS) Cryptographic
Protocol for Providing the Connectionless-mode Network Service Authentication", RFC 3567, July 2003.
ISO/IEC 10589:2002 Second Edition.
[RFC3784] Li, T., Smit, H., "IS-IS extensions for Traffic
Engineering", RFC 3784, June 2004.
[IS-IS-CAP] Vasseur, J.P. et al., "IS-IS extensions for advertising [RFC3784] Smit, H. and T. Li, "Intermediate System to Intermediate
router information", draft-ietf-isis-caps, work in progress. System (IS-IS) Extensions for Traffic Engineering (TE)",
RFC 3784, June 2004.
[RFC3567] Li, T. and R. Atkinson, "Intermediate System to [RFC4971] Vasseur, JP., Ed., Shen, N., Ed., and R. Aggarwal, Ed.,
Intermediate System (IS-IS) Cryptographic Authentication", RFC 3567, "Intermediate System to Intermediate System (IS-IS)
July 2003. Extensions for Advertising Router Information", RFC
4971, July 2007.
[PCED-OSPF] Le Roux, Vasseur, et al. "OSPF protocol extensions for [RFC5088] Le Roux, JL., Ed., Vasseur, JP., Ed., Ikejiri, Y., and
Path Computation Element (PCE) Discovery", draft-ietf-pce-disco- R. Zhang, "OSPF Protocol Extensions for Path Computation
proto-ospf, work in progress. Element (PCE) Discovery", RFC 5088, January 2008.
11.2. Informative References 11.2. Informative References
[RFC4657] Ash, J., Le Roux, J.L., "PCE Communication Protocol Generic [PCED-MIB] Stephan, E., "Definitions of Managed Objects for Path
Requirements", RFC4657, September 2006. Computation Element Discovery", Work in Progress, March
2007.
[PCEP] Vasseur, Le Roux, et al., "Path Computation Element (PCE) [PCEP] Vasseur, JP., Ed., and JL. Le Roux, Ed., "Path
communication Protocol (PCEP) - Version 1", draft-ietf-pce-pcep, work Computation Element (PCE) communication Protocol (PCEP)
in progress. ", Work in Progress, November 2007.
[PCED-MIB] Stephan, E., "Definitions of Managed Objects for Path [RFC4655] Farrel, A., Vasseur, JP., and J. Ash, "A Path
Computation Element Discovery", draft-ietf-pce-disc-mib, work in Computation Element (PCE)-Based Architecture", RFC 4655,
progress. August 2006.
[RFC4655] Farrel, A., Vasseur, J.P., Ash, J., "Path Computation [RFC4657] Ash, J., Ed., and J. Le Roux, Ed., "Path Computation
Element (PCE)-based Architecture", RFC4655, august 2006. Element (PCE) Communication Protocol Generic
Requirements", RFC 4657, September 2006.
[RFC4674] Le Roux, J.L., et al. "Requirements for PCE discovery", [RFC4674] Le Roux, J., Ed., "Requirements for Path Computation
RFC4674, October 2006. Element (PCE) Discovery", RFC 4674, October 2006.
12. Editors' Addresses: Authors' Addresses
Jean-Louis Le Roux (Editor) Jean-Louis Le Roux (Editor)
France Telecom France Telecom
2, avenue Pierre-Marzin 2, avenue Pierre-Marzin
22307 Lannion Cedex 22307 Lannion Cedex
FRANCE FRANCE
Email: jeanlouis.leroux@orange-ftgroup.com EMail: jeanlouis.leroux@orange-ftgroup.com
Jean-Philippe Vasseur (Editor) Jean-Philippe Vasseur (Editor)
Cisco Systems, Inc. Cisco Systems, Inc.
1414 Massachusetts avenue 1414 Massachusetts avenue
Boxborough , MA - 01719 Boxborough, MA 01719
USA USA
Email: jpv@cisco.com EMail: jpv@cisco.com
13. Contributors' Adresses:
Yuichi Ikejiri Yuichi Ikejiri
NTT Communications Corporation NTT Communications Corporation
1-1-6, Uchisaiwai-cho, Chiyoda-ku 1-1-6, Uchisaiwai-cho, Chiyoda-ku
Tokyo 100-8019 Tokyo 100-8019
JAPAN JAPAN
Email: y.ikejiri@ntt.com EMail: y.ikejiri@ntt.com
Raymond Zhang Raymond Zhang
BT Infonet BT
2160 E. Grand Ave. 2160 E. Grand Ave.
El Segundo, CA 90025 El Segundo, CA 90025
USA USA
Email: raymond_zhang@bt-infonet.com EMail: raymond.zhang@bt.com
14. Intellectual Property Statement Full Copyright Statement
Copyright (C) The IETF Trust (2008).
This document is subject to the rights, licenses and restrictions
contained in BCP 78, and except as set forth therein, the authors
retain all their rights.
This document and the information contained herein are provided on an
"AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS
OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND
THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS
OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF
THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED
WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
Intellectual Property
The IETF takes no position regarding the validity or scope of any The IETF takes no position regarding the validity or scope of any
Intellectual Property Rights or other rights that might be claimed to Intellectual Property Rights or other rights that might be claimed to
pertain to the implementation or use of the technology described in pertain to the implementation or use of the technology described in
this document or the extent to which any license under such rights this document or the extent to which any license under such rights
might or might not be available; nor does it represent that it has might or might not be available; nor does it represent that it has
made any independent effort to identify any such rights. Information made any independent effort to identify any such rights. Information
on the procedures with respect to rights in RFC documents can be on the procedures with respect to rights in RFC documents can be
found in BCP 78 and BCP 79. found in BCP 78 and BCP 79.
skipping to change at page 16, line 8 skipping to change at line 752
attempt made to obtain a general license or permission for the use of attempt made to obtain a general license or permission for the use of
such proprietary rights by implementers or users of this such proprietary rights by implementers or users of this
specification can be obtained from the IETF on-line IPR repository at specification can be obtained from the IETF on-line IPR repository at
http://www.ietf.org/ipr. http://www.ietf.org/ipr.
The IETF invites any interested party to bring to its attention any The IETF invites any interested party to bring to its attention any
copyrights, patents or patent applications, or other proprietary copyrights, patents or patent applications, or other proprietary
rights that may cover technology that may be required to implement rights that may cover technology that may be required to implement
this standard. Please address the information to the IETF at this standard. Please address the information to the IETF at
ietf-ipr@ietf.org. ietf-ipr@ietf.org.
Disclaimer of Validity
This document and the information contained herein are provided
on an "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE
REPRESENTS OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE
IETF TRUST AND THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL
WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY
WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE
ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS
FOR A PARTICULAR PURPOSE.
Copyright Statement
Copyright (C) The IETF Trust (2007). This document is subject to the
rights, licenses and restrictions contained in BCP 78, and except as
set forth therein, the authors retain all their rights.
 End of changes. 99 change blocks. 
317 lines changed or deleted 321 lines changed or added

This html diff was produced by rfcdiff 1.34. The latest version is available from http://tools.ietf.org/tools/rfcdiff/