RE: draft-gan-fast-reroute-00.txt

["Metz, Eduard" <Eduard.Metz@KPNQwest.com>]

Hi,

haven't read the draft in detail yet, but adding support for SRLG to avoid
detours to be routed over links that share the same risk seems very
useful.Sometimes even a plain requirement to deploy fast re-route in a
usefull way. As an example consider the situation described in section 2,
when link 1-2 and link 1-3 run in the same cable both the main LSP and the
potential detour are affected by a single cable-cut. Leaving you with
regular re-route.

Some other questions:
- What will happen if the detour from Node1 to Node3 (picture section 2)
passes Node4? Will the detour terminate at Node4, or will the traffic will
pass link 3-4 two times?
- Similar to the above, but now for the case where the detour passes the
Egress?

Thanks.

cheers,
	Eduard

> -----Original Message-----
> From: Ping Pan [mailto:pingpan@juniper.net]
> Sent: 13 April 2001 01:41
> To: curtis@avici.com
> Cc: dhg@juniper.net; arthi@juniper.net; kireeti@juniper.net;
> mpls@UU.NET; ccamp@ops.ietf.org
> Subject: Re: draft-gan-fast-reroute-00.txt
> 
> 
> Curtis Villamizar wrote:
> > 
> > > > It should be fine to provide a object that names a 
> specific node as a
> > > > special case of the detour object, and may be (is) needed to
> > > > accommodate existing code.  It might be useful to have 
> a form of the
> > > > detour object that covered the link disjoint special 
> case.  There
> > > > should also be a form of the detour object that allows the more
> > > > general list of SRLG.
> > > >
> > > > SRLG should also be considered in the "Detour Path Computation
> > > > Algorithm" section.
> > >
> > > Sure. Thanks!
> > 
> > So you'll add one or two Objects to cover SRLG, and 
> possible the link
> > disjoint special case.
> > 
> 
> Let me check with other folks here. We have shipped the restoration
> feature for a while, and providers have deployed it. So we have to be
> careful. Please understand.
> 
> Thanks again!
> 
> - Ping
>