Are SW upgrades needed in MPLS core networks?

Fri Feb 6 19:40:09 UTC 2004

Rubens Kuhl Jr. wrote:

>>There is another factor at play here which is memory bandwidth at the
>>lookup engine. If you have to look deeper into the packet than you can
>>accomplish by using single spin trough the thing that fetches x bit wide
>>words from the packet, you´ll effectively half your packet rate.
>>    
>>
>
>Yes, that might explain the performance halving in some architetures (may be
>it's what happens with Sup 720, may be not), instead of longer lookup cycle.
>
>  
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I have the understanding that catalyst line uses 48 bit access. Wonder 
where they got that from :-)

So when forwarding to single end hosts, you might end up with one third 
of the performance of IPv4. However I have not confirmed this but you 
might want to bother your sales engineer.

>>Doing 8+1+1+1+1+... would seem wasteful for IPv6 with the current
>>address allocation scheme, are you sure that´s what´s used for IPv6 too?
>>    
>>
>
>I'm not. Juniper isn't very open about this matter, and I only got
>confirmation of that for IPv4.
>  
>
I think they also put that in a public document, probably due to the 
fact that Cisco put theirs in first. I haven´t seen a document 
discussing structures either one uses for IPv6 but I have been told they 
are "different for performance reasons".

Pete