[c-nsp] Getting ready to pull the trigger: RSP720/SUP720

[Rick Ernst]

On Mon, April 6, 2009 08:12, Jon Lewis wrote:
> On Mon, 6 Apr 2009, Rick Ernst wrote:
>
>> I'm planning on collapsing the border/core into a pair of
>> 7600/Sup720-3BXLs, and it looks like they will be almost idle with this
>> amount of load.
>
> That really depends on the features you enable.  Try doing full netflow on
> a sup720 doing a few hundred mbit's of traffic, and they're suddenly not
> so mighty.

Yikes!  Does DFC on the linecards mitigate this?  I'm also looking
specifically at the Sup720/MSFC3/PFC3BLX.


>> The problem I am running into is spec'ing the aggregation layer.  Almost
>> all of our traffic is ethernet now, and all the interfaces need
>> bi-drectional rate-limiting/traffic-shaping/policing.  We have a
>> variable
>> bandwidth model and need to cap traffic at 1Mbs granularity. 1,5, and
>> 10Mbs connections are common, and 20,50,100Mbs connections exist with a
>> 200Mbs pipe in process.
>
> We've been using 3550's for years for this, as they have the ability to
> police in both directions, per port, at whatever granularity you like.
> The 3560, which was supposed to be an improvement/replacement for the 3550
> lost this ability, which really shocked me when I configured my first one.
> It can do per-port output shaping, but the granularity kind of blows.
> You're limited to 1/N * port rate, where N is an integer from 0 to 65535.
> This gives plenty (actually a huge waste of range) of granularity at the
> low end of bandwidth, but at the high end, you're limited to full rate,
> 50%, 33%, 25%, 20%, etc.  If I'm wrong here, I'd love to hear it and be
> told how to limit a 100mbit port to say 40mbit/s.


It looks like the 3550 has been EOLd for a couple of years.  Does the 3750
(non-Metro) or other comparable switch carry the same functionality?  Does
the switch itself need to be doing IP on the port to provide rate-liming? 
Input shaping is where my major concern is since these would be deployed
where traffic is heavily weighted on inbound (from-the-customer).


Thanks!