1. Page - 1IETF 76, Hiroshima, November 8-13, 2009 Explicit Control of Region Boundary for PCE-Based Inter-Layer draft-lin-pce-ccamp-multilayer-lsp-00.txt Xihua Fu Xuefeng Lin Gang Xie ZTE Corporation

2. Page - 2IETF 76, Hiroshima, November 8-13, 2009 Scenario The procedure of higher-layer signaling trigger model based on [RFC4206].RFC4206

3. Page - 3IETF 76, Hiroshima, November 8-13, 2009 Problem Without cooperating with VNTM or policy configuration, in order to trigger the lower layer signaling, an intermediate LSR has to determine regions boundaries by using the IGP database and EROs as described in RFC4206.RFC4206 An application where a TED could be held centrally (e.g., on a distinct LSR that supports PCE) for centralized computation is foreseen. But if there is not any or enough TED within the intermediate LSR, it could not determine regions boundaries during the signaling.

4. Page - 4IETF 76, Hiroshima, November 8-13, 2009 Explicit control of regions' boundaries PCE can determine regions' boundaries. After PCE compute an end-to-end paths across multi-layer, multi-layer EROs should be carried in PCRep and Path. In order to explicitly control regions boundaries, this draft introduce a new object carried in PCRep and Path message. Regions' boundaries could be carried in this new object (ERBO- Explicit Region Boundary Object).

5. Page - 5IETF 76, Hiroshima, November 8-13, 2009 Example 1

6. Page - 6IETF 76, Hiroshima, November 8-13, 2009 Example 2

7. Page - 7IETF 76, Hiroshima, November 8-13, 2009 Example 3

8. Page - 8IETF 76, Hiroshima, November 8-13, 2009 Requirement for extension A requirements for PCRep (RFC5440) extensions to support explicit control of region boundary is foreseen.RFC5440 A requirements for Path (RFC3473) extensions to support explicit control of region boundary is also foreseen.RFC3473 A new object could be introduced in PCRep and Path message. The format of new object is the same as an ERO.

9. Page - 9IETF 76, Hiroshima, November 8-13, 2009 Updated PCRep Message Formats ::= ::= [ ] ::= [ ] ::= [ ] ::=[ ] [ ] [ ] [ ] ::= [ ]

10. Page - 10IETF 76, Hiroshima, November 8-13, 2009 Updated Path Message Formats ::= [ ] [ [ | ]... ] [ ] [ ] [ ] [... ] [ ] [... ] ::= [ ]

11. Page - 11IETF 76, Hiroshima, November 8-13, 2009 Next Steps The solution should not be limited to specific Inter-Layer Path Computation and Inter-Layer Path Control Models. The solution should also be applied in the situation where TED can be maintained by the intermediate LSR in order for less signaling time. More detailed solution will be soon.