Subject: RFC 3036: Label Mapping Question

From: "Sharma, Prem" <[email-masked]>
Date: Tue, 21 May 2002 15:52:26 -0700

Hi,

I've one question on LDP. What should be the behaviour of the LDP module
when it receives the label mapping message for a FEC when the label
retention mode is liberal and that FEC (e.g. partial IP prefix) is not
visible to the local routing module? Should it store the label just received
or send out label release message? Here, the routing module just doesn't
have any information abt. this IP prefix. On querying, the routing module
returns "route not available" or "no information abt. the route". 

As per the LDP specs., it's implicit/apparent that label distribution
entities and routing entities should work in tandem and should remain in
synch. So, what should be the behaviour in this special case where LDP sees
some FEC but that FEC is not visible to routing entity? 

The following from RFC 3036, doesn't talk abt. this case explicitly:
LMp.12 Is MsgSource the Next Hop for FEC? If so, goto LMp.14.
Should the boolean expression in the step mentioned above be considered
"FALSE" in this specific scenario?
Any response will be greatly appreciated.
Thanks.
Prem

---

From: "Chetan Pinto" <[email-masked]>
Date: Sun, 26 May 2002 00:02:39 -0700

>or send out label release message?

"Should" store it

>Here, the routing module just doesn't

Before the Routing information could be propagated,
the label mapping may be sent.
This may be 'cos of a timing difference between the
LDP and Routing entities [due to implementation behaviour].
The Routing entity may be able to send the routing information later
[say in a time frame of a few seconds after the label mapping message]

>Any response will be greatly appreciated.

chetan

_________________________________________________________________
MSN Photos is the easiest way to share and print your photos: 
http://photos.msn.com/support/worldwide.aspx