Subject: RE: A fundamental question

From: Irwin Lazar <[email-masked]>
Date: Wed, 2 May 2001 12:31:58 -0600

Is their a table available that compares/contrasts ATM vs. MPLS?
Thanks, Jeremy.

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Have a look at:
http://www.mplsrc.com/faq2.shtml#MPLS and ATM

Irwin

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From: "Naidu, Venkata" <[email-masked]>
Date: Thu, 3 May 2001 11:35:08 -0400

Hi David

Please look at my inline comments:

-> There is no way that an ATM-specific setup can know what IP routes
-> exist.  So if any auto-VC setup is going to happen, it must either be
-> traffic-driven (which will not perform well in a network core) or a
-> full-mesh must be pre-established.

There were protocols, like I-PNNI and PAR (PNNI Augmented Routing)
developed long before MPLS started which does the same job you stated.
And there was IETF Working group ION (Internetworking Over NBMA) also.
 
-> Now, if you want to go and invent a new ATM that uses IP routing
-> protocols in order to fix this, go right ahead.  But that's not what
-> MPLS is trying to do.

I accept, For that matter, MPLS has learned all good experiences
from ATM MPOA, Ipsilon's IP Switching, Cisco's Tag Switching, IBM's ARIS,
Toshiba's CSR and so many trailed proprietary switching technologies.

[snip]
-> ATM's routing and signaling protocols are closely tied to ATM's
-> addressing architecture.  These protocols are not based on 
-> IP, and they
-> do not scale up to networks the size of the internet.  

No David, These (ATM Signaling/Routing) protocols are very much designed
to scale for networks as large as 'I'nternet. Esp designed keeping in mind
with the growth of the Internet & addressing. But they didn't get
(we didn't give) chance to let them prove.

-> ATM is not an IP protocol.

I accept! To conclude MPLS is making "connection-less IP to connection 
oriented (at the core) with the power of so many L2 technologies integrated
and a single IP L3 network overlaid on top of so many L2s efficiently."

And all those other L3 protocols/networks designed for all specific
L2's are no more!

-Venkata Naidu