Subject: RE: header

From: Eric Gray <[email-masked]>
Date: Mon, 19 Jun 2000 09:29:07 -0700

> -----Original Message-----
> From: Ramanjaneyulu Y T [mailto:[email-masked]]
> Sent: Sunday, June 18, 2000 12:23 PM
> To: [email-masked]
> Subject: header 
> 
> 
> IP over MPLS
> 
> some packets may be normal IP packets (having only IP header), 
> whereas some may be MPLS packets(having MPLS header followed 
> by IP header).
> 
> how does one distinguish whether it is an IP packet, or an 
> MPLS packet.

If you check out the encapsulation draft, at:

http://www.ietf.org/internet-drafts/draft-ietf-mpls-label-encaps-07.txt

you will find that there are protocol identifiers used at 
layer 2 to demux labeled and unlabeled packets for PPP and
Ethernet/802.3.

Both ATM and Frame Relay assume use of a separate VC to
carry unlabeled packets.

>                                           With  Regards
>                                         Ramanajaneyulu Y.T. 

--
Eric Gray