Subject: ATM-LSR

From: Deepak Jain <[email-masked]>
Date: Mon, 15 Nov 1999 19:37:53 +0530

Hi, 
    draft-ietf-mpls-ldp-06.txt gives that we need to use TCP and UDP for
LDP based discovery and session establishment messages. If this is so
then how is MPLS implemented on ATM switches that do not have Transport
layer protocols (TCP/UDP)?

Is there a way to use LDP without using TCP/UDP? Being new to MPLS, am I
missing something very obvious?

Regards
Deepak

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From: Rohit Chhapolia <[email-masked]>
Date: Mon, 15 Nov 1999 09:27:58 -0500

Deepak,

> layer protocols (TCP/UDP)?

For control purposes, you would need TCP and UDP to run LDP. However, you are
not required to have these in data path.

Rohit

-- 
Rohit Chhapolia
Ficon Technology, Inc.
mailto:[email-masked]
http://www.ficon-tech.com

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From: "Peter Ashwood-Smith" <[email-masked]>
Date: Mon, 15 Nov 1999 09:43:04 -0500

> missing something very obvious?

  The ATM-LSRs must be running IP/TCP/UDP or you cannot run MPLS on them.
Normally one of the VCCs on a port is configured to run classical IP on 
ATM. It is over this VCC that all normal IP traffic flows and it is over
this VCC that OSPF/RIP etc. will operate to establish connectivity. TCP
then operates over this VCC also and is used by MPLS for label requests
and mappings.

  These mapping messages then result in additional VCC's being allocated
for the actual MPLS datapaths.

  Hope this helps,

  Peter Ashwood-Smith