[c-nsp] NPE-G1 PPS limitations

[Hank Nussbacher]

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