[c-nsp] GSR12008|GRP-B|4OC12/ATM-MM-SC|3GE-GBIC-SC throughput?

[Lamar Owen]

On Tuesday 14 April 2009 18:22:03 Jason Lixfeld wrote:
> For the life of us, we can't seem to get any more than 60Mbps
> sustained across the ATM testing with iperf, so we're just trying to
> figure out if the GSR just can't push any more than what it's doing or
> if there's something else afoot.
[snip]
> We've done our due diligence to ensure the bits of the network between
> the test machine and the ATM can support 100Mbps, so we're fairly

Hmm, 60mb/s using a 100mb/s connected box sounds about right.  To really 
strain an OC12 you need a gigabit connected tester that can really do a 
gigabit of traffic.  Or multiple test PC's. 

I have a 12012 here in production, and have some of the kit necessary to test 
point to point ATM connections (including a Catalyst 8540MSR with OC12, ARM, 
and gigabit cards), and have a 4xOC12/ATM/MM, but it will be a few days before 
I could have the time to set up a test to see if the 12012 is limited.  The LC 
engines on the ATM card and the 3GE card will be the limiting factor, and 
those cards are rated for line rate on four simultaneous OC12's or line rate 
on two GigE (can't do full line rate on all three with a 2.5Gb/s fabric 
connection).  The GRP CPU is not involved in the data plane on a GSR; the LC 
engine CPU's/ASICs do dCEF and talk directly over the fabric.  Unless you have 
serious fabric issues preventing full bandwidth, in which case you have bigger 
problems.

So I'd first check to see if your iperf test box can really generate sufficient 
traffic.

What sort of ATM switch or router is on the other end of those multimode short 
reach OC12's?  What sort of router is terminating them?  How are your PVC's 
set up?