The MPLS WG Archive

[Curtis Villamizar <curtis@workhorse.fictitious.org>]

In message <4B6D09F3B826D411A67300D0B706EFDE84A47C@nt-exch-yow.pmc-sierra.bc.ca
>, Shahram Davari writes:
> I was not talking about IP control path. I was talking about "RSVP-TE Reverse
>  path". Having RSVP-TE reverse path is not an MPLS requirement.
> 
> -Shahram


LSP Ping does not require an RSVP-TE reverse path.  The ICMP echo
reply is delivered to the IP address of the sender.  Its and IP
packet.  It doesn't need an LSP but if one is there it can use it.

Curtis


> > -----Original Message-----
> > From: Curtis Villamizar [mailto:curtis@workhorse.fictitious.org]
> > Sent: Monday, December 17, 2001 5:18 PM
> > To: Shahram Davari
> > Cc: 'curtis@fictitious.org'; Ping Pan; Ash, Gerald R (Jerry), ALCTA;
> > mpls@UU.NET
> > Subject: Re: MPLSOAM BOF meeting draft minutes 
> > 
> > 
> > 
> > In message 
> > <4B6D09F3B826D411A67300D0B706EFDE84A47B@nt-exch-yow.pmc-sierra.bc.ca
> > >, Shahram Davari writes:
> > > Curtis,
> > > 
> > > Could you please explain this part a bit more, I can't 
> > understand your point.
> > > 
> > > -Shahram
> > > 
> > > > 4) Ping's proposal depends on the RSVP-TE return path, 
> > while Harrison's pro
> > > po
> > > > sal does not depend on
> > > > any specific MPLS control plane.
> > > 
> > > 
> > > >If two LSRs can't talk to each other using the IGP routes and IP
> > > >forwarding except during a brief IGP convergence transient 
> > if the IGP
> > > >routes just changed (which would imply a recent link 
> > failure) the ISP
> > > >will have plenty of "hints" to indicate that something is very
> > > >seriously wrong.
> > 
> > 
> > If two LSRs can't send IP packets between each other, then enough is
> > broken that the ISP has to notice it.  Plenty of alarms would be going
> > off.  I think any IP network operator would get this and I'm surprised
> > that anyone didn't.
> > 
> > In other words, there had better be an IP return path.  If you are
> > complaining that a problem may exist in some flavor of MPLS that
> > doesn't use an IP control plane and where the ingress and egress
> > cannot communicate via IP, then IMHO you can't expect to be taken very
> > seriously in any IETF WG.
> > 
> > Curtis