[c-nsp] Output queues - access vs. trunk

Mikael Abrahamsson swmike at swm.pp.se
Sat Jul 20 00:44:37 EDT 2013

On Fri, 19 Jul 2013, Jerry Bacon wrote:

> When the the ports facing the radios are in access mode, everything is 
> good, but when they are in trunk mode (which we need), we get 2 - 3% 
> packet loss at small packet sizes (high packet rates). We've tracked it 
> down to output queue drops, but I don't understand why it's different 
> for access vs. trunk.

Please describe more in detail what your configuration is like.

If the fluke is connected to an access port, you then vlan tag the traffic 
on the trunk port, then you're adding 4 bytes per packet meaning your 
access port is no longer wire speed and the loss you're seeing would be 

> Any ideas? And would QOS tuning be likely to help?

QOS is a way of selecting what packets to drop. I don't see how it would 
help here.

Mikael Abrahamsson    email: swmike at swm.pp.se

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