The MPLS WG Archive

["Vach Kompella" <vkompella@timetranetworks.com>]

Yes, the "tunnel" labels don't change.  However, if an implementation
"indiscriminately" uses all labels to hash on, then it would use the VC label
for data packets, and VC + OAM label for OAM packets, yielding a not so nice
result.

In that sense, it "would be nice" to suggest that a BCP should be to ignore
reserved labels.  While various implementations may not be able to follow this
guideline, it is still a reasonable suggestion, somewhat along the lines of
saying don't use certain fields in the IP header for hashing.

-Vach

> -----Original Message-----
> From: owner-mpls@UU.NET [mailto:owner-mpls@UU.NET]On Behalf Of Thomas D.
> Nadeau
> Sent: Wednesday, November 20, 2002 6:15 AM
> To: Alia Atlas
> Cc: David Allan; 'MPLS@UU.net'
> Subject: RE: Load balancing draft
>
>
> At 10:40 PM 11/19/2002 -0500, Alia Atlas wrote:
> >At 05:45 PM 11/19/2002 -0500, Thomas D. Nadeau wrote:
> >>         Not necessarily. I think you can test/trace the paths using LSP
> >> ping,
> >>but of course, there is a price to pay for that too; there is no free lunch.
> >>The advantage of the latter is that it works with all of the hardware
> >>deployed today.
> >
> >How does it work today with the pseudo-wire case?  From the draft, it
> >seems that the same PW label is used, but it is not the bottom of stack,
> >b/c there is an explicit NULL underneath.
> >
> >So, suddenly one must forward based not only on the MPLS label but also
> >the  bottom-of-stack bit...
> >
> >Tell me I'm missing something here, but if the above is really what is
> >intended in the draft, I don't understand how you can claim that it is
> >compatible with current MPLS hardware.
>
>          It is my understanding that tracing the PW "tunnel" LSP is the
> same as any
> other MPLS LSP.
>
>          --Tom
>
>
>