[c-nsp] C6800 Sup2T buffering ?

[james list]

Dear experts
my customer have some multicast flows which are detected sometime with
peaks/latency.

They measure this latency based on protocol financial feed timestamp which
I'm not able to decode (I guess they use stuff like Corvil).

The path from the market datafeed source to the customer is:

Financial market --1Gb -- C6807 VSS SUP2T  -- 10 G port-channel WAN --
C6807 VSS SUP2T -- 1 Gbs -- Arista 7150S --1 Gbs -- customer

They report 10-15 ms average latency and sometimes they detect 500-600 ms.

Following the path I do not find anything telling me there are spikes (I
have no drops) and also the customer states no packet loss is detected, but
we suspect buffering/queuing somewhere on C6807 or Arista 7150S.
Since Arista 7150S is low latency I suspect Cisco.

Some questions:
- what do you suggest to check here ? buffers ? qos ? other...
- what I can use to try to decode pcap taken on Arista switch to check if
the latency is really obtained checking protocol market timestamp ?

Thanks in advance for any hint or help.

Cheers
James