[nsp] [nsp] Forwarding latency corellated to CPU utilization

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Hi,

I suffer the same problem with 12.0(21)ST with tag switching disabled

The delay in RTT increases every 1 minute, at the same time BGP process scans the routing table. There´s an explanation at http://www.cisco.com/warp/public/459/highcpu-bgp.html

Rgds.

ML

>All,
>
>I have recently encountered interesting phenomenon:
>
>On cisco 7206 working in a typical configuration in ISP >environment (BGP, ISIS, MPLS), I have noticed that traffic forwarded from ATM interface (PA-A3-OC3) to T1 interface (PA-8CT1) is prone to increased forwarding latency (up to 700ms!) while CPU utilization
is high (during typical spikes while BGP scenner or ISIS SPF runs).

This is happening only when forwarded packets are arriving as MPLS,
and egressing as normal IP HDLC frames. In other words, router is
removing MPLS label (penultimate hop).

As soon as I disabled tag switching on ATM, problem is gone.

IOS version is 12.2(8)T4.

Is it a feature or bug?

I can replicate it easily.

Thanks,

Przemek

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