Subject: RE: initiating a discussion on mpls singaling protocols

From: Shahram Davari <[email-masked]>
Date: Fri, 26 Jul 2002 08:14:55 -0700

Giles,

> 
> I want *both* mp2p LDP and targetted LDP.
> 
> I want the former because it:
> 
> 1) minimises the number of labels required in the core - O(N) rather
> than O(N squared).
> 

I think Heinrich Hummel demonstrated in the Japan (as predicted by Dave Allan)
that mp2p (LDP) results only ~15% less states than N^2 mesh. 

-Shahram

---

From: Giles Heron <[email-masked]>
Date: 26 Jul 2002 16:43:49 +0000

> that mp2p (LDP) results only ~15% less states than N^2 mesh. 

I didn't see Henrich's demonstration :(

From what I remember he relies on an assumption of per interface label
state to achieve this (i.e. consider label L received on interface X and
forwarded to interface Z to be a different state to label L received on
interface Y and forwarded to interface Z).  This assumption is correct
for some MPLS P devices - but not AFAIK for those which are deployed
most commonly.

And of course the results will vary depending on the ratio of P to PE
devices and the on the network topology...

Giles

-- 
=================================================================
Giles Heron    Principal Network Architect    PacketExchange Ltd.
ph: +44 7880 506185              "if you build it they will yawn"
=================================================================