1. MPLS-TP Loopback Draft draft-boutros-mpls-tp-loopback-02.txt Sami Boutros and a Cast of Thousands

2. Background This draft specifies how to put a bi- directional MPLS LSP into and out-of loopback mode. This draft specifies two forms of the mode –Intrusive: loop all traffic (including data) or –Non-instrusive only OAM messages, not data traffic

3. Problem Definition LSR-1 LSR-2 LSR-3 MPLS Bidirectional LSP MEP1MIP2MEP3 Operator at MEP1 needs to –Set a loopback at a chosen MIP or MEP to –Loop all traffic –Loop only specific OAM traffic In the case of full loopback, a capability is needed to first take the LSP out of service

4. Proposed Solution: LSP into Intrusive Loopback Mode LSR-1 LSR-2 LSR-3 MPLS Bidirectional LSP LSR-1 sends a Lock Request to LSR-3 to take the MPLS LSP out of service LSR-3 takes the MPLS-LSP out of service from dataplane and sends an Ack back to LSR-1 LSR-2 setup dataplane to loopback traffic received on this LSP from LSR-1 and sends an ack back to LSR-1 LSR-1 sends a Loopback Request to LSR-2 To put the MPLS LSP in Full Loopback mode

5. Proposed Solution: Intrusive Loopback Mode, flow of data packets LSR-1 LSR-2 LSR-3 MPLS Bidirectional LSP LSR-1 sends data packets on the MPLS Bidirectional LSP to test connectivity up to LSR2, Packets may contain a sequence #’s. LSR-2 Loops back the packets sent to LSR-1 LSR-1 could check sequence #’s on packet received to guarantee no losses

6. Putting MPLS-TP in Loopback using NMS An operator should be able to provision any given LSR to: 1.Lock/Unlock any MPLS-TP LSP. 2.Setup any MPLS-TP LSP in loopback mode (either FLB or OLB). 3.Send MPLS OAM packets from a MEP and notify NMS when MPLS OAM response arrives. When NMS is used to provision any of the above the functionality, the corresponding MPLS OAM message is not used.

7. Proposed Solution MPLS OAM Message extensions The proposed mechanism is based on two messages and A few TLVs which can be transported using one of the following methods: –in-band MPLS OAM messages which are forwarded as MPLS packets (non-IP based). –LSP-Ping messages where IP/UDP packets are used (IP-based) in compliance with RFC 4379.

8. Changes from -02 Reorganized TLVs into –two messages –some operation codes –very few TLVs

9. Message Format 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Version | Message Type | Operation | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Return Code | Cause Code | Message Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Sender's Handle | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Message ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | TLV's | ~ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

10. To be added Details of using LSP Ping

11. Issues How does this fit with the overall OAM tool set? –E.g. is an independent OAM loopback required or is it just duplicative of CV ping function? What should be the complete OAM organization of ACH code points, message types, function codes –E.g. lock is necessary for full loopback, but needed for other functions as well

12. Recommendation This draft, along with other OAM drafts, BFD and MPLS Ping be input to MEAD team effort to organized a complete OAM tool set