[c-nsp] 7600 DFC upgrade time ?

[vince anton]

> The pps limit of EARL7 is packet size agnostic, only headers are
> transmitted. And actually it's not EARL7 that craps out at ~30Mpps,
> it's the bus, the bus is fully saturated with pushing packets
> for EARL7 to do it's lookup.
>
> I think it's like 32btes per cycle, IP is 2 cycles and MPLS is
> 3 cycles (since it needs IP if you do ECMP). Bus is 62.5MHz, I think.
> So from this we'd arrive at:
>
> (62.5*1000000)/2/1000000 = 31.25Mpps IP
> (62.5*1000000)/3/1000000 = 20.83Mpps MPLS
>
> This of course assumes that bus will only have headers for lookup,
> that is, you don't have classic LC's that use bus for transferring
> data.


ok, so if its just the headers that go to the PFC, when using CEF-720 LCs
without DFCs, and IPv4 only traffic (no MPLS, no IPv6), then it looks like
the 'sh catalyst6000 traffic-meter' is more true to the real load that the
box can handle than I originally thought.  Of course you need to watch the
fabric channel load as well for the actual data going through.


cheers

anton