Priority queue for voice/audio traffic

Question

Hi,
Still in limbo after multiple discussions with our vendors, TAC and in general other engineers, so starting a thread here.  In the process of rolling out enterprise audio, with the intent to prioritize and allocate 25% of link bandwidth for voice class.
Our config snapshow is as follows -
policy-map qos-wan-out
 class dscp-voice-lan
  set ip precedence 5
  priority percent 25
I understand that
-DURING congestion, this will ensure voice gets a maximum of 25% and is dequeued first due to the priority setting
-And during NO congestion, the voice traffic will be dequeued before other traffic, but at the same time, can go over 25% as QoS kicks in only during congestion.
I am seeing some contradictory results in that we are having high packet loss if we exceed 25% even when the link is less than 40% utilized. I doubt the above CE configurations are an issue. But, wanted to run this by this group.
Alternate theory is that with the above configurations, our traffic is exiting fine - but the service provider who is using priority class queuing within their MPLS network may be capping the bandwidth at 25% at all times (with or without congestion).
thanks

Answer 1

Hi Bro
Maybe the incoming voice packets into your FW isn't marked with ef. For this reason, you don't see anything at all. I hope the QOS isn't tied to a subinterface, as QOS is only supported on the main interface itself. What you're doing here is QoS Configuration based on DSCP. You could refer to this URL for troubleshooting purposes.
http://www.cisco.com/en/US/products/ps6120/products_configuration_example09186a008080dfa7.shtml#tab4
Did you marked on the Cisco Catalyst switchports, which ports are ef?