[c-nsp] NPE-G1 PPS limitations

[Hank Nussbacher]

On Fri, 18 Apr 2008, Arie Vayner (avayner) wrote:

> The way the buses are built on the 7200 create a bandwidth bottle neck
> for the PA slots. I would say 400M is the limit per bus (there are 2,
> and the PAs are split between them).
> You should be aware of the concept of bandwidth points with regards to
> PA slots on 7200:
> http://www.cisco.com/en/US/prod/collateral/routers/ps341/prod_presentati
> on09186a008009184d.pdf
> http://www.cisco.com/en/US/docs/routers/7200/configuration/7200_port_ada
> pter_config_guidelines/3875In.html
>
> On NPE-G1/G2, the onboard (on the NPE) GigE ports are different, and are
> not limited by this kind of configuration as they are wired directly to
> the forwarding engine.
> There is also another exception for adding another PA slot on NPE-G1/G2,
> by using the Jacket Card:
> http://www.cisco.com/en/US/docs/routers/7200/configuration/7200_port_ada
> pter_config_guidelines/3875In.html#wp1100537

There is no mention that a PA-GE can be slotted into the Jacket card.  Am 
I missing something?

Thanks,
Hank

> http://www.cisco.com/en/US/prod/collateral/routers/ps341/prod_bulletin09
> 00aecd80471892.html
>
> Arie
>
> -----Original Message-----
> From: cisco-nsp-bounces at puck.nether.net
> [mailto:cisco-nsp-bounces at puck.nether.net] On Behalf Of Hank Nussbacher
> Sent: Friday, April 18, 2008 07:28 AM
> To: Ross Vandegrift
> Cc: cisco-nsp at puck.nether.net
> Subject: Re: [c-nsp] NPE-G1 PPS limitations
>
> On Thu, 17 Apr 2008, Ross Vandegrift wrote:
>
>> On Thu, Apr 17, 2008 at 11:35:13AM -0700, dpinkard at AccessLine.com
> wrote:
>>> Would one expect gigE to gigE traffic local to the NPE-G1 to scale
>>> higher than that?
>>
>> Yea, I would expect that.  I don't understand all of the
>> architechtural issues on the 7200 series in great detail, but it seems
>
>> that either the PCI bus that line cards use isn't really up to doing
>> GigE, or the controllers on the PA-GE doesn't scale well.
>>
>> The router I saw this on originally had it's primary ingress interface
>
>> on the NPE and primary egress interface on the PA-GE.  When we swapped
>
>> a low-traffic interface on the NPE with the PA-GE, we suddenly saw our
>
>> packet loss drop to nothing.  So I can say with pretty much 100%
>> confidence that local to the NPE will scale much better than the
>> PA-GE.
>>
>> Ross
>
> Have others found this as well?  So far we have used the builtin GE
> ports on the G1 and have not seen problems.  We are planning on adding a
> 4th GE port via a PA-GE and had not seen any documentation about the
> limitations you mention.
>
> Thanks,
> Hank
> _______________________________________________
> cisco-nsp mailing list  cisco-nsp at puck.nether.net
> https://puck.nether.net/mailman/listinfo/cisco-nsp
> archive at http://puck.nether.net/pipermail/cisco-nsp/
>