[NSP] Maximum High Speed Interfaces on 3640

[Alex Foster]

I know Cisco claim the maximum number of High speed interfaces supported by
the 3640
is two - but is it possible to run 4 without maxing out the CPU.  I have
tested the 3640
with 2 ATM OC3 modules and 1 FE module and average about 60-70% util. on
load.  If I introduce
another FE interface the CPU maxs out.  Are there any
workarounds/configuration tricks to
overcome this - or is this a case of "it does exactly what is says on the
box".  The 3640 has
128MB memory and the iomem is set to 30/70 split.

I am also curious to find out if anybody has overcome the limitations of the
OC3 module
and its pretty dire throughput.   I appreciate the module is not designed to
operate at
wire speed by the most I have got out of one module is around 45 to 50 Mbps.
Any
tips/advise would be appreciated.  Again cisco claim you can achieve upto
80Mbps
throughput with larger packet size - excuse my ignorance here - is this
achieved by increasing
the MTU on the ATM interface/sub-interface??

Regards

Alex