RE: GSR, 7600, Juniper M?, oh my!

["Jason Frisvold" <friz () corp ptd net>]

> -----Original Message-----
> 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