[j-nsp] b/w limit M320 FPC2

[Richard A Steenbergen]

On Thu, Apr 06, 2006 at 04:11:11PM +0200, Alexander Koch wrote:
> Folks,
> 
> FPC2 nominally do 10G, and then nominally 2.5G per PIC.
> Think about the 4xGE PIC and 4 of them on a FPC2. How
> 'dynamic' is that setup going to be, and what is the hard
> limit for one of these PICs under these circumstances?

I could tell you what I've seen from M160 FPC2's, but I assume on M320 it 
is going to be completely different.

The story I've heard is that outside of the new FPC4s for OC768/etc (which 
have true 40G asics), the M320/T series architecture only has 20G 
forwarding ASICs. Thus a T640 FPC3 is 2x20G, a T320/M320 FPC3 is 1x20G, 
but FPC2 and FPC1s are also 1x20G (also each FPC has its own Internet 
Processor type asics, and does distributed IP lookups). This is completely 
different from the M160 architecture, which is just a dumb FPC talking to 
4 individual SFMs, each of which provide 3.2Gbps of capacity into the FPC 
(so that when all 4 SFMs are operating you get 12.8Gbps of capacity into 
an FPC2).

Can anyone confirm if the M320 FPC2's actually make a full 20G of 
bandwidth (or close to it minus overhead) available, so that filling it 
with PB-4GE PICs is not oversubscribing it?

-- 
Richard A Steenbergen <ras at e-gerbil.net>       http://www.e-gerbil.net/ras
GPG Key ID: 0xF8B12CBC (7535 7F59 8204 ED1F CC1C 53AF 4C41 5ECA F8B1 2CBC)