1. IETF 97@Seoul, South Korea
PCEP Link-State extensions for Segment Routing draft-li-pce-pcep-ls-sr-extension-01
Zhenbin Li (Huawei)
Xia Chen (Huawei)
Nan Wu (Huawei)
IETF South Korea

2. What’s new in version 01
None. The 00 version draft had been uploaded one year ago (2015/11/2) and this is our first time to present.

3. Purpose of the draft
In order to fulfill the need for applications that require visibility of SR paths across IGP areas or even across ASes, this draft defines extensions for the mechanism introduced in PCEP-LS to propagate SR information in those scenarios that have no IGP SR extension or BGP-LS running.

4. What’s PCEP-LS ?
Full name : PCEP Extension for Distribution of Link-State
Collect many important things :
1) link-state : local/remote IP addresses, local/ remote interface identifiers, link metric
2) TE : TE metric, link bandwidth, reservable bandwidth, per CoS class reservation state and so on
Finally PCCs send them via PCEP protocol to PCEs who need to perform its computations

5. So what’s SR ? Full name : Segment Routing
Leverages the source routing paradigm
Allows for a flexible definition of end-to-end paths within IGP topologies by encoding paths as sequences of topological sub-paths, called "segments“
These segments are advertised by the link-state routing protocols (IS-IS and OSPF)

6. Problems
If SR paths need to across BGP Ases or across IGP areas but I have no BGP-LS runnings, what should we do to view all paths?
Optical scenario ,BGP is not available

7. New additional TLVs
Import new additional TLVs in LSRpt message which is defined in PCEP-LS new message
TLV Code Point
Message
Description
Length
Value defined
TBD1
PCEP LSRpt
SID/Label Binding
variable
[ISIS-SR]#section2.4
TBD2
SR-Capabilities
[ISIS-SR]#section3.1
TBD3
SR-Algorithm
[ISIS-SR]#section3.2
TBD4
Adjacency Segment
[ISIS-SR]#section2.2.1
TBD5
LAN Adjacency Segment
[ISIS-SR]#section2.2.2
TBD6
Tunnel Segment
[tunnel segment-SR]　
TBD7
Prefix Segment
[ISIS-SR]#section2.1.2
Import 7 new additional TLVs ( 6 TLVs have already been defined in IGP segment routing extensions , the last one is defined in Tunnel Segment in Segment Routing) in LSRpt message of PCEP protocol to map segment routing information
TBD6:used to identify a tunnel of any kind in a segment routing network

8. Next Steps
Solicit comments.
Revise the draft.
Thank you!