From: Alex Rubenstein [mailto:alex@nac.net]
On the 7500, you have RSPs and VIPs; the former performing routing
protocol work, vty's, RIB's, etc., the latter doing actually packet
forwarding.
While this sounds great on paper, our experience has us shying away from
dCEF and looking for something bigger and better... dCEF pushed the RSP
processor down to about 5%, but pushed up the VIP processors to about
90-95%...
VIP-Slot0>sh proc c
CPU utilization for five seconds: 13%/12%; one minute: 14%; five
minutes:
15%
I wish we could get our routers to do this...
Obviously, we run dCEF, which puts the VIP's in the position of
forwarding
everything on their own, as evidenced by the CPU measurements.
But each VIP is responsible for it's own traffic, so if a particular VIP
runs most of the traffic, it has much higher CPU usage... In our case,
we have a router loaded with VIP 4-50's and Enhanced ATM OC-3
adapters... Originally, we had a single OC-3 running about 120-130 Megs
constant and the VIP CPU was at 90-95%.... To combat this, we had to
put in additional OC-3 cards with additional VIPs and distribute the
load... Still, high CPU is a problem .. For instance :
CPU utilization for five seconds: 63%/63%; one minute: 63%; five
minutes: 65%
30 second input rate 78227000 bits/sec, 17858 packets/sec
30 second output rate 47944000 bits/sec, 12778 packets/sec
It seems to me that we should be able to do sooo much better... *sigh*
OC-12 adapters are an option, but they are rather expensive ...
However, to answer your question, even a modestly configured 7507 with
RSP4, and VIP2-50's will be substantially more capable than a
7206-NPE300.
Things may change on the NPE-400 or G1, but I have no direct
experience
with that.
The G1 processors, so far, have proven to be wonderful... We only have
experience with them running in the 7200 uBR chassis, but they've shown
a huge reduction in CPU utilization...
PS. Regards to stability; we have SUBSTANTIAL improvements in IOS
stability, especially in 12.3.5a mainline.
Heh.. *old* Cisco code scares me enough... Bleeding edge is simply
terrifying... *sigh*
-- Alex Rubenstein, AR97, K2AHR, alex@nac.net, latency, Al Reuben --
-- Net Access Corporation, 800-NET-ME-36, http://www.nac.net --
Jason Frisvold
Backbone Engineering Supervisor
Penteledata
