The MPLS WG Archive

[Hummel Heinrich <Heinrich.Hummel@icn.siemens.de>]

NO, the savings are much more. They are about 85 % reduction, so that 15 % remains.( I will not talk down these savings)
However, 0.15  * O(n**2) will still be far too much, if n is big enough.

Note that method (4) as of draft-hummel-mpls-n-square-investigations-00.txt also uses merging H-LSPs as to reduce the
costs at the PEs, e.g. down to 0.15 * O(n**2). 

But I also pointed out that even this is not good enough, if n = 7500 for example. For VPNs of such size, we should even form groups of sites (e.g. all sites within one city form a group)
and may have:
a) a partial mesh of elementary LSPs (which form a tree, a ring, a ring of trees, a tree of rings,or a chessboard grit)
b) a full mesh of hierarchical LSPs between the groups of sites
c) a full mesh of hierarchical LSPs between the sites of each group of sites

In order to accomplish effective full mesh connectivity, it may be appropriate to advertise all these LSPs (their ingress
and their egress, as well as their starting labels, etc.) - roughly spoken.
 
Of course it will take more labor, more conceptual thinking. E.g. so that the VC-label handling is integrated rather than
an "abuse" :-)


Heinrich



-----Ursprüngliche Nachricht-----
Von: Shahram Davari [mailto:Shahram_Davari@pmc-sierra.com]
Gesendet: Freitag, 26. Juli 2002 17:15
An: 'Giles Heron'; neil.2.harrison@bt.com
Cc: mpls@UU.NET
Betreff: RE: initiating a discussion on mpls singaling protocols


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