The MPLS WG Archive

[Jay Karthik <jkarthik@avici.com>]

At 04:35 PM 2/11/02 +0200, Doug Degan wrote:
>ping, thanks for the quick answer but looks like I didn't understand it or
>wasn't clear enough in my question :
>
>I was refering to the time of failure. not to the time after failure when
>the bypass is being used already.
>
>I assume bypass LSP is ready, and primary LSP is protected by it.
>then a failure occures somewhere between the PLR and the MP.
>the MP will probably get PATH-TEAR message because of it (also all the
>routers between the failure and the MP will get it) but the MP shouldn't
>send it downstream!!! because the lsp is not going to be teared from the MP
>to the Egress.
>
>to this problem I didn't find solution in the draft.

Doug,

As you said, the PathTear message will not be propagated downstream
until the MP  has received tear-down from all merging LSPs and
Section 3.2.2. (Procedures for the Merge Point) does describe it.

>thanks again.
>----- Original Message -----
>From: "Ping Pan" <pingpan@juniper.net>
>To: "Doug Degan" <doug_degan@hotmail.com>
>Cc: <mpls@UU.NET>
>Sent: Sunday, February 10, 2002 8:52 PM
>Subject: Re: fast-reroute question
>
>
> > Doug Degan wrote:
> >
> > > hi.
> > >
> > > I have another question regarding pan's draft in BYPASS method:
> > >
> > > 1) how does upstream routers act upon receiving of PATH TEAR message?
> > > there should be different activity between normal router and MP - but
> > > how does a router know he is active MP for a given LSP?
> > >
> > > if he does - he shouldn't tear it, but if he is just transit router - he
> > > should tear it!
> > >
> >
> >
> > When there is a network problem, the protected LSPs will use the bypass
> > LSP, and initiate Path Messages that will merge at MP. At this point,
> > it's a bunch of RSVP sessions using SE. When you get a PathTear, just
> > act according to what RSVP had defined.... kill the session and
> > associated branches.
> >
> > - Ping
> >
> >
> > >
> > >
> > > thanks in advance.
> > >
> > > doug.
> > >
> > >
> > >
> >
> >
> >