Cisco Support Community
Showing results for 
Search instead for 
Did you mean: 

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. And see here for current known issues.

New Member

Call manager QOS issues


customer is a bank main site hists the CUCM and there are 4 Branches.

All of the Branches when calling the Main site have no issues.

All of the branches have problems when calling the other branches.

Internal calls come across the GRE tunnel. So what happening is the branches are having one way call issues and drops.

QOS has been implemented along with bandwidth control via the locations in CUCM.

What else should I be looking for to correct the issues.


Re: Call manager QOS issues

One thing to be mindful of is QoS with GRE tunnels. QoS will be kicked off when the tx-ring of an interface is full and packets will be dropped when the interface is congested.

These two attributes aren't directly correlated with a GRE tunnel, so it's best to do a hierarchical shaper. This will limit the GRE to a bandwidth value and won't oversubscribe the WAN.


class-map voice

match protocol rtp audio

class-map skinny

match protocol skinny

policy-map shaper-parent

class class-default

shape average 1544000

service-policy shaper-child

policy-map shaper-child

class voice

priority 1000

class skinny

bandwidth 75

interface tunnel 1

service-policy out shaper-parent

For your one way voice problems you need to make sure that each of your sites have unique addressing space. If they have overlapping address space you're going to run into problems when those phones want to talk to each other.

Otherwise, every site is going to need reachability from phone-to-phone at each site. If you pull up the phone webpage during a call with one-way audio you'll see the address it's trying to connect to in the stream statistics.