[c-nsp] Will the Cisco 2911 push GigE with NAT enabled ?

[Tim Franklin]

> that's the figure for 64 byte packets.  For imix the feature-free result
> will be quite a chunk higher.  But then every feature you add (NAT, policy
> routing, full dfz, etc) will cause the performance to drop off significantly.

Take into account also that all Cisco's figures in the performance sheets are one-way.  180M means *total*, so effectively a 90M symmetric load.

I've tested the 2921 to 450M symmetric (so 900M Cisco-speak) of IMIX traffic with no features.  With QoS policies applied at all, performance drops to 40M (with an LLQ) or 70M without.  NAT, much as I try not to care about misfeatures, takes another 10-15% off those numbers.

You should be able to scale appropriately from the 2921/2911 paper comparison.

3900s will comfortable pass 1G symmetric IMIX traffic - this was limited by the physical interface rather than CPU.  I don't know with *just* NAT, no QoS.  (QoS performance was around 300M for the 3925e).

Regards,
Tim.