Subject: Need clarification on draft-ietf-pwe3-control-protocol-01.txt

From: Wei Luo <[email-masked]>
Date: Tue, 18 Mar 2003 11:14:24 -0800

Here is a question regarding reseting sequence numbers:

The pseudowire created for PWE3 traffic is made of a bi-directional LSP.  The
pseudowire state is considered as UP when having both local and remote label
with a particular vc id.  When one of these labels is removed (for example,
local or remote interface goes down), the pseudowire state is considered as
DOWN.

With sequencing turned on both directions, when the local label is withdrew and
a new local label is advertised while the remote label is intact, what should
the local PE expects the next sequence number is for disposition?

There could be two different answers:

1. Because the pseudowire of its entirety is bi-directional, when the pseudowire
goes DOWN and UP again, the sequence numbers should restart from 1 for both
directions.  Therefore, the local PE should expect the disposition packet with
sequence number 1.

2. The local PE should treat the pseudowire traffic unidirectionally, therefore,
the local PE should expect the disposition packet with sequence number n+1,
where n is the last sequence number received before the pseudowire flapped.

Which one should we stay with?

Thanks,

---Wei