draft-ietf-ccamp-ospf-interas-te-extension-03.txt   draft-ietf-ccamp-ospf-interas-te-extension-04.txt 
Network working group M. Chen Network working group M. Chen
Internet Draft Renhai Zhang Internet Draft Renhai Zhang
Expires: October 2008 Huawei Technologies Co.,Ltd Expires: October 2008 Huawei Technologies Co.,Ltd
Category: Standards Track Xiaodong Duan Category: Standards Track Xiaodong Duan
China Mobile China Mobile
April 10, 2008 April 11, 2008
OSPF Extensions in Support of Inter-AS Multiprotocol Label Switching OSPF Extensions in Support of Inter-AS Multiprotocol Label Switching
(MPLS) and Generalized MPLS (GMPLS) Traffic Engineering (MPLS) and Generalized MPLS (GMPLS) Traffic Engineering
draft-ietf-ccamp-ospf-interas-te-extension-03.txt draft-ietf-ccamp-ospf-interas-te-extension-04.txt
Status of this Memo Status of this Memo
By submitting this Internet-Draft, each author represents that By submitting this Internet-Draft, each author represents that
any applicable patent or other IPR claims of which he or she is 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 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 becomes aware will be disclosed, in accordance with Section 6 of
BCP 79. BCP 79.
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
skipping to change at page 1, line 36 skipping to change at page 1, line 36
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
The list of current Internet-Drafts can be accessed at The list of current Internet-Drafts can be accessed at
http://www.ietf.org/ietf/1id-abstracts.txt http://www.ietf.org/ietf/1id-abstracts.txt
The list of Internet-Draft Shadow Directories can be accessed at The list of Internet-Draft Shadow Directories can be accessed at
http://www.ietf.org/shadow.html http://www.ietf.org/shadow.html
This Internet-Draft will expire on October 10, 2008. This Internet-Draft will expire on October 11, 2008.
Abstract Abstract
This document describes extensions to the OSPF version 2 and 3 This document describes extensions to the OSPF version 2 and 3
protocols to support Multiprotocol Label Switching (MPLS) and protocols to support Multiprotocol Label Switching (MPLS) and
Generalized MPLS (GMPLS) Traffic Engineering (TE) for multiple Generalized MPLS (GMPLS) Traffic Engineering (TE) for multiple
Autonomous Systems (ASes). OSPF-TE v2 and v3 extensions are defined Autonomous Systems (ASes). OSPF-TE v2 and v3 extensions are defined
for the flooding of TE information about inter-AS links which can be for the flooding of TE information about inter-AS links which can be
used to perform inter-AS TE path computation. used to perform inter-AS TE path computation.
skipping to change at page 3, line 11 skipping to change at page 3, line 11
Intellectual Property Statement................................17 Intellectual Property Statement................................17
Disclaimer of Validity.........................................18 Disclaimer of Validity.........................................18
Copyright Statement............................................18 Copyright Statement............................................18
1. Introduction 1. Introduction
[OSPF-TE] defines extensions to the OSPF protocol [OSPF] to support [OSPF-TE] defines extensions to the OSPF protocol [OSPF] to support
intra-area Traffic Engineering (TE). The extensions provide a way of intra-area Traffic Engineering (TE). The extensions provide a way of
encoding the TE information for TE-enabled links within the network encoding the TE information for TE-enabled links within the network
(TE links) and flooding this information within an area. Type 10 (TE links) and flooding this information within an area. Type 10
opaque LSAs [RFC2370] are used to carry such TE information. Two top- opaque Link State Advertisements (LSAs) [RFC2370] are used to carry
level TLVs are defined in [OSPF-TE]: Router Address TLV and Link TLV. such TE information. Two top-level Type Length Values (TLVs) are
The Link TLV has several nested sub-TLVs which describe the TE defined in [OSPF-TE]: Router Address TLV and Link TLV. The Link TLV
attributes for a TE link. has several nested sub-TLVs which describe the TE attributes for a TE
link.
[OSPF-V3-TE] defines similar extensions to OSPFv3 [OSPFV3]. It [OSPF-V3-TE] defines similar extensions to OSPFv3 [OSPFV3]. It
defines a new LSA, which is referred to as the Intra-Area-TE LSA, to defines a new LSA, which is referred to as the Intra-Area-TE LSA, to
advertise TE information. [OSPF-V3-TE] uses "Traffic Engineering advertise TE information. [OSPF-V3-TE] uses "Traffic Engineering
Extensions to OSPF" [OSPF-TE] as a base for TLV definitions and Extensions to OSPF" [OSPF-TE] as a base for TLV definitions and
defines some new TLVs and sub-TLVs to extend TE capabilities to IPv6 defines some new TLVs and sub-TLVs to extend TE capabilities to IPv6
networks. networks.
Requirements for establishing Multiprotocol Label Switching Traffic Requirements for establishing Multiprotocol Label Switching Traffic
Engineering (MPLS-TE) Label Switched Paths (LSPs) that cross multiple Engineering (MPLS-TE) Label Switched Paths (LSPs) that cross multiple
Autonomous Systems (ASes) are described in [INTER-AS-TE-REQ]. As Autonomous Systems (ASes) are described in [INTER-AS-TE-REQ]. As
described in [INTER-AS-TE-REQ], a method SHOULD provide the ability described in [INTER-AS-TE-REQ], a method SHOULD provide the ability
to compute a path spanning multiple ASes. So a path computation to compute a path spanning multiple ASes. So a path computation
entity that may be the head-end Label Switching Router (LSR), an AS entity that may be the head-end Label Switching Router (LSR), an AS
Border Router (ASBR), or a Path Computation Element (PCE [PCE]) needs Border Router (ASBR), or a Path Computation Element (PCE [PCE]) needs
to know the TE information not only of the links within an AS, but to know the TE information not only of the links within an AS, but
also of the links that connect to other ASes. also of the links that connect to other ASes.
In this document, two new separate Link State Advertisements (LSAs) In this document, two new separate LSAs are defined to advertise
are defined to advertise inter-AS TE information for OSPFv2 and inter-AS TE information for OSPFv2 and OSPFv3 respectively, and three
OSPFv3 respectively, and three new sub-TLVs are added to the existing new sub-TLVs are added to the existing Link TLV to extend TE
Link TLV to extend TE capabilities for inter-AS Traffic Engineering. capabilities for inter-AS Traffic Engineering. The detailed
The detailed definitions and procedures are discussed in the definitions and procedures are discussed in the following sections.
following sections.
This document does not propose or define any mechanisms to advertise This document does not propose or define any mechanisms to advertise
any other extra-AS TE information within OSPF. See Section 2.1 for a any other extra-AS TE information within OSPF. See Section 2.1 for a
full list of non-objectives for this work. full list of non-objectives for this work.
2. Problem Statement 2. Problem Statement
As described in [INTER-AS-TE-REQ], in the case of establishing an As described in [INTER-AS-TE-REQ], in the case of establishing an
inter-AS TE LSP traversing multiple ASes, the Path message [RFC3209] inter-AS TE LSP traversing multiple ASes, the Path message [RFC3209]
may include the following elements in the Explicit Route Object (ERO) may include the following elements in the Explicit Route Object (ERO)
skipping to change at page 5, line 5 skipping to change at page 5, line 5
information for the CE-PE links. There is no overlap between this information for the CE-PE links. There is no overlap between this
document and [L1VPN-OSPF-AD]. document and [L1VPN-OSPF-AD].
2.2. Per-Domain Path Determination 2.2. Per-Domain Path Determination
In the per-domain method of determining an inter-AS path for an MPLS- In the per-domain method of determining an inter-AS path for an MPLS-
TE LSP, when an LSR that is an entry-point to an AS receives a Path TE LSP, when an LSR that is an entry-point to an AS receives a Path
message from an upstream AS with an ERO containing a next hop that is message from an upstream AS with an ERO containing a next hop that is
an AS number, it needs to find which LSRs (ASBRs) within the local AS an AS number, it needs to find which LSRs (ASBRs) within the local AS
are connected to the downstream AS so that it can compute a TE LSP are connected to the downstream AS so that it can compute a TE LSP
segment across the local AS to one of those LSRs and forward the PATH segment across the local AS to one of those LSRs and forward the Path
message to it and hence into the next AS. See Figure 1 for an example: message to it and hence into the next AS. See Figure 1 for an example:
R1------R3----R5-----R7------R9-----R11 R1------R3----R5-----R7------R9-----R11
| | \ | / | | | \ | / |
| | \ | ---- | | | \ | ---- |
| | \ | / | | | \ | / |
R2------R4----R6 --R8------R10----R12 R2------R4----R6 --R8------R10----R12
: : : :
<-- AS1 -->:<---- AS2 --->:<--- AS3 ---> <-- AS1 -->:<---- AS2 --->:<--- AS3 --->
 End of changes. 6 change blocks. 
14 lines changed or deleted 14 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/