The MPLS WG Archive

[Bala Rajagopalan <BRaja@tellium.com>]

Hello,

> 
> 
> 1. You need to specify both ingress and egress identifiers 
> for two reasons:
> 	a) On broadcast media (think GigE, 10 GigE) when a router has 
> multiple interfaces attached to the same switch, you want the RSVP 
> packet and MPLS LSPs to use the correct adjacency. And the only way 
> to get that is to specify a pair. This scenario is commonly used in 
> POP architectures where there are two GigE switches in the middle and 
> each router has one link to each GigE switch and the GigE switches 
> are interconnected.

What is the meaning of "correct adjacency" here? Specifically,
is there any reason for distinguishing between such adjacencies
ariori at the source? (Or, is there any reason why this 
sort of decision cannot be left as a local
matter to previous hop node?)
> 
> 2. I just asked a simple question with respect to fast reroute: How 
> do you do it when you have unnumbered interfaces. At first thought, I 
> thought it would be very hard to do, after thinking about it for a 
> few minutes I think if you make certain assumptions and make 
> extensive use of the IGP-TE database, you can possibly get by. But 
> why? Why are we arguing over 4 more bytes in the signaling message. 
> We don't have 56K leased line links any more. OC192c has become the 
> standard and 768c is right around the corner. I don't see any point 
> it haggling on four bytes. Hence we defined the EERO.

Actually, I'm just trying to understand the motivation and problem w.r.t
reroute. It would really help if you can describe the 
problem in some detail. 

Regards,

Bala