[c-nsp] Resilience in order of few hundreds of milliseconds

[Alaerte.Vidali at nokia.com]

Hi Aaron,

This is exactly where I am trying to get. I have seem that headend is
notified of failure on the path. (Cisco and Juniper)
But I never measured the convergence time using Path Protection. I hope
somebody could comment on this and if there are possibilities to make
Path Protection faster.

I will try to set up a lab and measure that.

Br,
Alaerte 

-----Original Message-----
From: ext Aaron Daubman [mailto:daubman at gmail.com] 
Sent: Tuesday, March 06, 2007 5:55 PM
To: Vidali Alaerte (Nokia-NET/RioDeJaneiro)
Cc: cisco-nsp at puck.nether.net
Subject: Re: [c-nsp] Resilience in order of few hundreds of milliseconds

Alaerte,

> When there is FRR support, we can use RSVP hellos; I am wondering way 
> Cisco does not support RSVP hellos being a mechanism to indicate 
> failure on logical tunnel interface from headend to tailend. The 
> headend would detect failure on option 1 and try option 2. (or if 
> there are two tunnel interfaces with diverse path and Multipath 
> Routing, when one logical interface goes Down traffic would be carried

> by other interface) Any comments?

Might MPLS TE Path Protection be what you are looking for?
http://www.cisco.com/en/US/products/sw/iosswrel/ps1829/products_feature_
guide09186a0080333d0d.html

IIRC, path failure can (and generally will) be indicated to the head-end
by both the IGP as well as RSVP messaging (although I cannot now locate
the reference I found that explicitly stated this, it did mention that
one's configuration and network details would determine whether the
headend would receive the IGP or RSVP update first...).
Perhaps somebody can confirm if this is how Cisco's MPLS Path Protection
is implemented?

Regards,
     ~Aaron