MLS QOS VOIP TRUST Command with 3560-X

marknigh1 · ‎09-23-2010

I wanted to post a question to the forum to see if anyone experience a problem I encounter today with QOS on the 3560-X (12.2(55)SE).

One of our customers is experiencing voice quality issues with their Nortel BCM. The good news is that are replacing there old nortel switches with Cisco 3560-X. Today we noticed that the class-map matching on DSCP EF on the router connected to the WAN wasn't getting hit so we enabled QOS on the port that is connected to the Nortel BCM to trust the packets (there should be both signaling and RTP coming from the BCM since it has voicemail). when we applied auto qos voip trust and try to make a call to a phone registered to the BCM, instead of ringback we heard continuous clicking. When I remove the mls qos trust dscp from the interface the clicking stopped instanteously and the ringback was heard. Apply the mls qos trust dscp command back on the clicking on the phone started again.

Thanks for your help

Lei Tian · ‎09-24-2010

Hi,

Can you post the configure for the interface having problem?

Today we noticed that the class-map matching on DSCP EF on the router connected to the WAN wasn't getting hit

So, the 3560 had qos enable globally, but nothing configured on the port? Can you post the output of 'show mls qos int stat' for the port connecting to Nortel BCM and the uplink port?

Regards,

Lei Tian

marknigh1 · ‎09-27-2010

here is the configuration for the port connected to the BCM server.

interface GigabitEthernet0/43
speed 100
duplex full
srr-queue bandwidth share 10 10 60 20
queue-set 2
priority-queue out
mls qos trust cos
auto qos voip trust

mls qos is enabled globally.

Interesting thing is that auto qos voip trust put in mls qos trust cos so I changed it to mls qos trust dscp (which broke it).

Lei Tian · ‎09-27-2010

Hi,

I can't tell what exactly went wrong at that point. I suspect the problem is related whether traffic was marked correctly. Can you share the configure on the uplink port, also the output of 'show mls qos interface g0/43 stat' and ' show mls qos interface uplink_port stat'.

Regards,

Lei Tian