Linksys SRW224G4P - Cisco phones dropping calls

Unanswered Question

I have a Linksys SRW224G4P with POE and I have 10 Cisco 7941 phones plugged into this.  When make calls internal or external the calls drop anywhere from 1 minute to 1 hour and I get a message on the phones that says Temp Fail and UCM down Features disasbled.  I use the linksys for phone training in conference rooms.   The linksys is plugged into a catalsyt 4506.  If I plug the phones into the catalyst i have no problems at all so I know its a linksys issue.  Can anyone explain???

I have this problem too.
0 votes
  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 0 (0 ratings)
chrcoope Mon, 10/26/2009 - 06:26


What VLANs are you running for voice and data? How are the uplink ports configured on both the Catalyst 4506 and the SRW224G4P? Are you using any form of QoS? Is IGMP snooping enabled on the SRW? From what VLAN DHCP pool do the phones Get issued an address when plugged into the SRW? And the Catalyst?



I have vlan 18 setup for phone on the linksys.  I am not using this switch for any data so i don't have any data vlans setup for that.  the uplink port on the linksys is in vlan 18 as well.  I have that connected to the catalyst in a regular port in the voip vlan, it is not a trunk port.  I have QOS enabled.  IGMP snooping is enabled on the linksys.

Can't figure out why calls establish and then all of a sudden they start to drop.  I have had a phone up for 45 mins then the call drops.  I have also had calls established for 30 secs then the call drops...let me know if you need any additional information.


chrcoope Mon, 10/26/2009 - 11:48

The phones want to use CoS tagging. If we do not use an 802.1q trunk, we cannot encapsulate the frame header. Without the encapsulation, there will be no place to put the CoS value.

Since we are talking about an SRW, it will be possible to use DSCP via DiffServ instead. the question will then be will the Catalyst honor/trust the DSCP values it receives from the SRW. I have attached a couple documents that should help you implement this. Two of these I have wrote, the other was written by another engineer and has yet to be "polished". This should be enough to get this done yourself however, should you require additional assistance, you may wish to contact the SBSC at 866.606.1866 and start a case. A WebEx session may be needed to finish the configuration.

I would also disable IGMP snooping unless it is properly configured on the network as it can block CDP.

To sum up, it sounds like the lack of appropriate QoS on the Skinny protocol is casing a disconnected state before the call is completed.

Hope this helps,



This Discussion