NAT table entries generate Interrupts?

Hello,

This is an enquiry prompted by threads: - Cisco 3620 and very low throghuput - CPU utilization on the router on comp.dcom.sys.cisco

Cisco say:

Cisco 10000 Series Routers Troubleshooting High CPU Utilization on Cisco Routers Document ID: 15095

... Each active translation generates CPU interrupts and has an impact on the total CPU utilization of the router. A very large number of translations can have a performance impact on the router.

####### End Cisco say: ########

This makes no sense to me. For what purpose might an interrupt be raised per NAT table entry?

Any suggestions anyone?

Seems either bad (well really, really bad) design or an incorrect statement. Since cisco don't do too much really bad design my money is on the latter.

However the docs are not too shabby either.

How large migh be "very large"?

If someone can come up with a reason for generating such interrupts how often might they be generated per table entry?

Ideas anyone?

Thanks.