Re: [mpls] [PWE3] ELI as a reserved label

[Greg Mirsky <[e-mail]>]

Dear Curtis,
interestingly, I was thinking of possible implications of EL and multipath
in FRR Facility backup network.
You wrote:
BTW - There are some implications for facilities FRR.  On the
facilities backup path there is no per LSP PATH or RESV message to
look at to see what value of ELI is being used.  If the facilities
backup path is over multipath (ie: LAG, bundle, or RSVP ECMP), then
the value of ELI will not be known.  This might force detour style FRR
or use of GMPLS path protection (or segement which is more
detour-like).  A fixed ELI would help here too (allowing bypass FRR).

If the protected link is LAG or Link bundle, then I think it is more likly
that LSPs will get squeezed as BW shrinks. Thus it might be not a local
protection but restoration that will be playing in.
Another scenario, a singleton link protected by a path that has LAG or Link
Bundle in it. I think that it would be up to local policy of the particular
PLR to signal use of EL on the bypass tunnel regardless of whether EL been
used on any of protected LSPs.

Regards,
Greg