PCEP-LS : Distribution of Link-State and TE Information via PCEP.
draft-dhodylee-pce-pcep-ls-01 draft-kondreddy-pce-pcep-ls-sync- draft-wu-pce-pcep-ls-sr-extension- optimizations-00 00 PCEP Extension for Distribution Optimizations of PCEP Link- PCEP Link-State Extensions for of Link-State and TE Information. State(LS) Synchronization Segment Routing Procedures Dhruv Dhody, Young Lee, Daniele Venugopal Reddy Kondreddy, Eric Wu , Zhenbin Li (Robin) Ceccarelli Mahendra Singh Negi
94th IETF @ Yokohama 1 Reincarnation!
In the past life, known Generalized to LS (link- as “draft-dhodylee-pce- state)! pcep-te-data-extn”. •Which includes TE of course!
94th IETF @ Yokohama 2 Introduction
[I-D.leedhody-teas-pcep-ls] (on agenda in TEAS) proposes PCEP based approach for learning and maintaining the Link-State and TE information. • Architectural considerations and options • And its impact
This document list • The requirements • The extensions for PCEP-LS.
94th IETF @ Yokohama 3 Applicability
When no IGP or BGP-LS running
• in the network • at the PCE
IGP or BGP-LS running, but
• Receive partial information from PCEP for faster convergence • Only Incremental update from PCEP • Or receive from both
Hierarchy of PCE / ACTN
94th IETF @ Yokohama 4 Requirements for PCEP extension
Capability Capability to report the Advertisement link-state (and TE) Mechanism to link Encode only the exact •Remote (learned) state information information learned via changes in link-state •Local and remote IGP and BGP-LS (and TE) properties •Support for initial sync
Support MPLS-TE, GMPLS, optical and PCE-PCE All architecture options impairment aware synchronization properties.
94th IETF @ Yokohama 5 LSRpt Message
PCC MUST report any changes in the link-state (and TE) information to the PCE by sending a LS Report carried on a LSRpt message to the PCE.
Each node and Link would be uniquely identified by a PCEP LS identifier (LS-ID).
•remains constant for the lifetime of a PCEP session
The LS reports may carry local as well as remote link-state (and TE) information
94th IETF @ Yokohama 6 Initial Sync
Initial Link-State (and TE) PCC takes a snapshot of data base synchronization the DB in a series of LSRpt Sync Flag in LS object immediately after PCEP message. session initialization.
94th IETF @ Yokohama 7 Optimizations
LS PCE-triggered PCE-triggered Incremental LS Synchronization Initial Re- Synchronization Avoidance Synchronization synchronization
To skip Link-State To let PCE re- (and TE) To do incremental To let PCE control the synchronize the Link- synchronization if the (delta) Link-State (and timing of the initial State (and TE) state has survived and TE) Synchronization Link-State (and TE) information for sanity not changed during when possible Synchronization. check. session restart.
PCE trigger by Using Link-State DB Synchronize only the PCE trigger by sending LSRpt from Version to find if the changes, since session sending LSRpt from PCE to PCC with LS- no change in the DB down. PCE to PCC ID=0 and SYNC=1
94th IETF @ Yokohama 8 TLV & Sub-TLV
Local and Link Prefix Routing- Remote Node Node Link Attribute Descriptors Descriptor Universe TLV Descriptor Attribute TLV TLV TLV TLV TLV
IP (v4/v6) local MT ID Autonomous System Local / remote ID /remote router-id MT ID Link Local/remote ID Node flags BGP-LS Identifier IP (v4/v6) interface Administration address Opaque node group properties OSPF Area ID OSPF Route Type Max BW
IP (v4/v6) neighbor Node Name address Max Resv BW IGP Router ID IS-IS area ID Un resv BW IP reach ability information MT ID MT ID IP (v4/v6) local router-id ….
94th IETF @ Yokohama 9 PCEP-LS and SR Use PCEP-LS to carry the SR New sub-TLV for Node information via PCEP Attribute TLV •Instead of IGP or BGP-LS •SID/Label Binding •SR-Capability •SR-Algorithm
New sub-TLV for Link New sub-TLV for Prefix TLVs Attribute TLVs •Prefix Segment •Adjacency Segment •LAN Adjacency Segment •Peer Segment •Peer-Set Segment
94th IETF @ Yokohama 10 Next Steps
Agree with the current approach?
Comments?
94th IETF @ Yokohama 11 Thanks!
94th IETF @ Yokohama 12