[c-nsp] DS-3 -> OC-3 upgrade

[Rick Ernst]

I'm currently looking at upgrading our border routers from DS-3 to
100Mbs/Ethernet or OC-3.  The routers are 7206VXRs with NPE-300/256MB. They
are each accepting full tables and are RR-clients for the core.

I've noticed with the DS-3s that CPU utilization is roughly 40% at 40Mbs of
in/out traffic (80Mbs aggregate).  I've also seen that over 40% that
latency increases through the router.  There is a small ACL (about 30
entries), plus RPF checks on inbound traffic.

Based upon this empirical evidence, I'm hesitant to go OC-3, or even 100Mbs
through them.  Do my numbers seem way off, or am I missing something?
Would upgrading to NPE-400 "surely be enough", or should I look at other
ways of bringing in higher-speed links?

Thanks,
Rick