1. draft-koike-mpls-tp-temporal- hitless-psm-01 28 th July. 2010 Maastricht Yoshinori Koike / NTT

2. Background *Carrier Grade packet transport network requires MPLS-TP OAM function to be effective in maintenance operations *If some faults or un-expected events occur, quick actions and methods are mandatory in terms of transport network requirements.

3. Network Objectives of transport network (1)The monitoring and maintenance of current transport paths has to be conducted in service without traffic disruption. (2)The monitored or managed transport path condition has to be exactly the same irrespective of any configurations necessary for maintenance.

4. Why segment monitoring ?  Quick location of fault point & prompt handling of the problem Segment monitoring function is mandatory in Delay Measurement and Loss Measurement (DM and LM is supported only between MEP and MEP) Diagnostic test and on-demand CV should be able to be conducted from an intermediate point of configured transport path.

5. Use cases of temporal segment monitoring NE1(LER1) CE2 CE1 NE2(LSR1)NE4(LER2)NE3(LSR2) Packet Delay/Loss Segment monitoring 1 Transport path Segment monitoring 2 No Fault Detect Fault Use case 1) DM and LM Use case 2) Diagnostic test and on-demand CV NE2(LER1) NE5NE1 NE4(LER2)NE3(LSR2) Segment monitoring 1 Segment monitoring 2 Originator of test packets Cost effective small box (Support a subset of functions)

6. Problem Statement regarding SPME (P-1) Increasing the bandwidth by the stacking shim header(s) (P-2) Increasing the identifier management of all MEPs and MIPs newly configured for SPME in the old MEG In case of temporal(on-demand) segment monitoring (P’-1) Changing the condition of the original transport path by changing the length of the MPLS frame (delay measurement and loss measurement can be sensitive) (P’-2) Disrupting client traffic over a transport path, if the SPME is temporally configured. In case of pre-configured segment monitoring

7. Potential issue of SPME ABCDE LBL= 110 LBL= 120 LBL= 130 Before LBL= 210 LBL= 220 LBL= 130 LBL= 100 Setting SPME LBL= 999 Change of Inner label value Change of outer label value After  There seems significant changes in the original transport path, if SPME is set for segment monitoring.  Performing monitoring function should not change the condition of target transport path

8. Conclusions Request to include two network objectives in page 3 in the MPLS-TP OAM framework. In addition Request solution for temporal & hitless path segment monitoring without problems like P-1, P-2, P’-1 and P’-2. (The solution may have to be considered independently from SPME issue) Note: This I-D is based on the liaison from ITU-T SG15, the solution is needed for the preparation of ITU-T MPLS-TP OAM Recommendation.

9. Next Steps Clarification of technical details of SPME and impacts on transport path in client layer Solution for temporal and hitless path segment monitoring Creating a new solution if problems are not solved by SPME Clarification of applicable segments in both per- node model and per-interface model Any possible patterns between MEP-MEP,MEP-MIP, MIP-MIP including internal NE monitoring Segment of protected transport path used for protection

10. Thank you Soliciting comments, feedback and suggestions for this draft from WG