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Extensions to OSPF-TE for Inter-AS TE
draft-ietf-ccamp-ospf-interas-te-extension-01.txt
Mach Chen([email protected]) Renhai Zhang([email protected])
IETF 69#, CCAMP WG Chicago 07/24/2007
Changes since Prague meeting(ietf 68th)
Adopted as a WG document
A new section , Section 2.1: “A Note on Non-Objectives”, is added to clarify some concerns about this I-D.
Make a clearly statement about “Not to do” in this document
A new section (Section 7), Acknowledgments, is added to thank Adrian, Acee, JP, and Dean Cheng for their review and comments.
Update references and add some new essential references ( according to the comments from Acee)
Some wording and formats changes to fix some nits
IETF 69#, CCAMP WG Chicago 07/24/2007
Changes since Prague meeting(cont.)
Address a technical point from Jean-Louis Le Roux about Link ID sub-TLV (should not be limited to TE Router ID)
Re-write the description about Link ID sub-TLV:
From:
“For an inter-AS link, the Link ID carried in the Link ID sub-TLV is the TE Router ID of the remote ASBR reached through this inter-AS link.”
TO:
“For an inter-AS link, the Link ID carried in the Link ID sub-TLV is the remote ASBR identifier which could be any address of the remote ASBR (i.e. the TE Router ID, Router ID or interface address of the remote ASBR) reached through this inter-AS link. Normally, the TE Router ID is recommended.”
IETF 69#, CCAMP WG Chicago 07/24/2007
Next step
Solicit inputs from OSPF WG
This I-D is very small and now stable.
IETF 69#, CCAMP WG Chicago 07/24/2007
Extensions to ISIS-TE for Inter-AS TE
draft-chen-ccamp-isis-interas-te-extension-01.txt
Mach Chen([email protected]) Renhai Zhang([email protected])
IETF 69#, CCAMP WG Chicago 07/24/2007
BackgroudExtensions to OSPF-TE is already a WG I-D.
Intra-AS TE links advertisement is OK.RFC3784 has defined how to advertise the intra-area TE links.RFC4205 and ISIS-TE-v3 define the similar extensions.
Inter-AS TE links advertisement is not defined yet (ISIS).
Extensions to ISIS-TE for inter-AS TEOptimization for selection of AS exit points,Identifying the AS and ASBR reached through each exit point.
Such inter-AS TE link information includes:List of all inter-AS TE links for the local ASTE properties of each inter-AS TE linkAS number of the neighboring AS and identity of the neighboring ASBR
connected to by each inter-AS TE link
Per-domain and BRPC both need such inter-AS TE link information
IETF 69#, CCAMP WG Chicago 07/24/2007
ProposalExtensions to ISIS-TE
Two new sub-TLVs are added to the Extended IS Reachability TLV.Remote AS number sub-TLVRemote ASBR ID sub-TLV
A new TLV is defined. ( the inter-AS reachability TLV )Same semantic and formats as the Extended IP Reachability TLV
Using Up/down bit, facilitate distribution inter-AS reachability info between tow levels
Inter-AS reachability TLV with two sub-TLVsRemote AS number sub-TLVRemote ASBR ID sub-TLV
IETF 69#, CCAMP WG Chicago 07/24/2007
Next step
Need more comments and feedback from WG
Solicit inputs from ISIS
Accept this draft as a WG I-D?
IETF 69#, CCAMP WG Chicago 07/24/2007
Comments?
Thanks!
IETF 69#, CCAMP WG Chicago 07/25/2007
Why Per-Domain needs inter-AS links?
Two typical scenarios:
AS2 looseAS2 looseAS3 looseAS3 loose
ERO ERO
B1 looseB1 looseC1 looseC1 loose
ERO ERO Scenario 1:Scenario 1:Locate Exit Locate Exit
ASBR based on ASBR based on AS number of AS number of
downstream ASdownstream AS
Egress Egress LSRLSR
IngressIngressLSRLSR
A1A1 C3C3
C2C2
A2A2
AS 1AS 1 AS 2AS 2 AS 3AS 3
B2B2A3A3 B4B4
C1C1B1B1 B3B3
Path MessagePath Message
Scenario 2:Scenario 2:Locate Exit Locate Exit
ASBR based on ASBR based on entry ASBR of entry ASBR of
downstream ASdownstream AS
IETF 69#, CCAMP WG Chicago 07/25/2007
PS:
Why BRPC needs inter-AS links?
Typical computation scenario for BRPCThe traversed domains are assumed to be selected before path
computation: AS1->AS2->AS3
Egress Egress LSRLSR
IngressIngressLSRLSR
A1A1 C3C3
C2C2
A2A2
AS 1AS 1 AS 2AS 2 AS 3AS 3B2B2A3A3 B4B4
C1C1B1B1 B3B3
PCE1PCE1 PCE2PCE2 PCE3PCE3
PCE3 and PCE2 need to select entry boundary nodes based on their upstream AS number respectively.
PCE2 and PCE1 need to select exit boundary nodes that provide connections to their downstream AS respectively.
IETF 69#, CCAMP WG Chicago 07/25/2007
PS:
Not to doNot trying to distribute TE information from one AS within
another AS.
Not trying to distribute any form of TE reachability information for destinations outside the AS
Not proposing any change to the PCE architecture or usage.
Not suggesting any TE aggregation.
IETF 69#, CCAMP WG Chicago 07/25/2007
PS:
