[mpls] draft-kompella-mpls-rmr-00

[Xuxiaohu <[e-mail]>]

Hi Kireeti,

I have read your draft and found it's very interesting.

I wonder whether it's possible to introduce the idea of the RPR (Resilient Packet Ring) technology into the MPLS-enabled ring networks. For instance, for a given node on a ring, it has two types of interfaces, one is ring-interface and the other is non-ring-interface. In addition, the ring-interface is either eastward or westward. When receiving an MPLS packet from a non-ring interface, if the next-hop of that MPLS packet is one of its adjacent peers on the ring, it would impose a label indicating clock-wise forwarding or count-clock-wise forwarding accordingly. When receiving an MPLS packet with the top label being the label indicating clock-wise or counter-clock-wise forwarding, unless the next-hop of the FEC which is indicated by the label below that top label is itself or a peer which is connected via a non-ring interface (i.e., the packet would pop off the ring), that packet should be forwarding according to the top label, e.g., if the top label indicates clock-wise forwarding, it would be forwarded in the clock-wise direction.

The label indicating clock-wise or count-clock-wise forwarding could be an SPL or a local label which is advertised by each ring node. If that label is a local label, it should be swapped accordingly on each hop of the ring. When the packet received from a adjacent peer on the ring should pop off that ring, the top label indicating clock-wise or count-clock-wise forwarding should be stripped before performing the further MPLS forwarding process.

Best regards,
Xiaohu