[c-nsp] 7500 RSP8 Throughput Ability

[Bill Wichers]

> My options:
>
> I have a large inventory of 7500 hardware.  I was thinking 7513, Dual
> RSP8's with 256MB of RAM.  VIP 4-80's with 256MB of RAM.  I will be
> using 4 PA-GE's and 1 Dual DS3 Chan cards.

I think you might run into memory issues with the RSP from all those BGP
sessions. The only real solution to this on the 7500 platform is the RSP16
which is expensive.

> As many of you will think, the 7200XVR with an NPE GE1 will be great
> here, but I do not have one to allocate and I like the idea of route
> processor redundance.  The other idea would be a 7300/7600/6500 all
> with a SUP720, but again, I would rather not go out and buy 1 $10K
> card when I have gear sitting around and the sup720 are not all that
> cheap on the used market these days.   Other then that, I could home
> this off a juniper, only to be plagued by GRE tunnel and Multilink
> issues.

I personally have not seen an RSP fail in active service, although I've
heard stories... I don't think RSP redundancy alone should be a big factor
in your decision making here, especially since you're currently using a
7200 w/o redundancy.

> The questions:
>
> Can you all give me an idea of what a 7513 running say 200 to 300MB a
> sec agg. traffic would see for CPU load?  Can anyone tell me what I
> can expect for a bandwidth limitation on the backplane of these
> chassis?  I am pretty sure I am on crack to even thinking I could do
> this, so any info at this point will be helpful (I have 	only loaded
> a 7500 up to around 70MB running D-CEF/IP cache flow and never been
> happy with the CPU load).  If you all concur that this is pushing the
> limits of the 7513, then sup720 it is.  Thanks a lot for the
> help.   //db

I think you could make this work. Most of the CPU load is going to be from
route table updates since dCEF is going to handle moving the packets
around as long as you aren't running anything to make a large amount of
packets get bumped to the RSP. We run about 50-100 Mb/s on a 7507 and see
only about 8-10% CPU on the RSP4, but everything is distributed and there
are only two BGP feeds to the box, and no down-stream customer feeds.

I think you could get your 200-300 Mb/s with the configuration you're
planning, but I don't think you'll have much upgrade room. Personally, if
you're looking at used hardware anyway, I'd look at a 12008 with a GRP-B
and whatever interfaces you need.

     -Bill


*****************************
Waveform Technology
Systems Engineer