Subject: Re: Message Transmission in GMPLS

From: Ashok Narayanan <[email-masked]>
Date: 03 Dec 2002 10:31:29 -0500

On Tue, 2002-12-03 at 03:56, Manoj Agiwal wrote:
> Hi ,
>       When RSVP messages are transmitted , what should be the source and
> destination IP addresses , should these IP addresses
>    be that of control plane or should these IP address be Node ID . Some
> vendors have chosen GRE tunnel to tunnel Signaling 
>    message across the control plane to the next node . The inside IP address
> being that of Nodes while routable address that of
>    control plane ethernet interface .
>       This can result in Interop Issues , IETF should enforce using one of
> the mechanism ,  or should the nodes be flexible enough
>     to expect both . Problem might come where the logic resolves around
> Source IP address from where the Signaling message 

Nodes should be flexible enough to accept both. The use of a stable
address (e.g. Router-ID or some shared GRE address) is better in that it
reduces messaging in the case of control channel failover. But it needs
routing. In any case, the receiving node should accept what it gets.

Source address is probably not as relevant for messages that carry HOP
objects (like a Path) as the reliable messaging peer is also extracted
from there. For messages that don't carry HOP objects the source address
may be important; but RFC2961 defines source address behaviour for ACK &
SREFRESH messages. 

With the exception of reliable messaging (perhaps), there should really
be no reason to have trouble with any source address of a message.

>     arrived .
> Regards ,
> Manoj