The MPLS WG Archive

[George Swallow <swallow@cisco.com>]

> Currently you'd have to do that from each PLR.  We don't provide a
> means to tell the ingress of the existance of a detour (except the
> local-protect-available bit in the signaling itself which one major
> implementation wasn't using last I checked).  We also don't provide a
> means to tell a specific PLR to exercise its detour and report back.
> 
> Let's wait and hear from Kireeti or other authors whether they think
> anything should be added or whether the intent is to require testing
> initiated at each PLR.

The PLR is responsible for the bypass.  It knows what sender-template
it used, so it can form the proper FEC for the ping.  It can send a
lsp-ping with the proper label stack.  So it is the natural place to
do this.  If it fails, it should

a) report to network management
b) reset the backup in place bit
c) look for another way of establishing a backup
d) if successful on c) set the backup in place bit.

You may want to put a hold-down on b) to avoid reporting to the
head-end on a transient situation.

I don't see what advantage you would gain by moving all this to the
head-end.  I do see a lot of complications...

...George


==================================================================
George Swallow       Cisco Systems                  (978) 497-8143
                     250 Apollo Drive
                     Chelmsford, Ma 01824