The Cisco IP Communicator is a Microsoft Windows-based SoftPhone application. It enables computers to function as Cisco Unified IP Phones and provides high-quality voice calls on the road, in the office, or from wherever users have access to the corporate network.
This document addresses some of the issues that occur when a call is made from a Cisco IP Communicator/Cisco IP Phone, as well as the solution to fix this problem.
Cisco recommends that you have knowledge of these topics:
The information in this document is based on the Cisco IP Communicator 7.x and Cisco 79xx Series IP Phones.
The information in this document was created from the devices in a specific lab environment. All of the devices used in this document started with a cleared (default) configuration. If your network is live, make sure that you understand the potential impact of any command.
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When you make calls, the Cisco IP Communicator/IP Phone displays this error message: CM Down Features Disabled.
This error message indicates that the call preservation feature is active because the application has lost its connection to CallManager.
The workaround for this or any other invocation of the call preservation feature is to hang up manually. If the phone does not return to normal on-hook behavior (all lines shown while idle, softkeys appropriately displayed, and responsive to user input), restart the Communicator application or the Cisco IP Phone.
If the above workaround did not fix the issue, it is recommended that you change the Station keepalive parameter to 60 or to its maximum allowed.
Note: Make sure that the IP phone can reach the Cisco Unified Communication manager. The IP reachablity issues can occur because of IP routing, VLANs, or multiple DHCP servers in the same network. Multiple DHCP servers can create problems if they assign a different subnet to the IP phone from which the IP phones cannot reach the CUCM server; this results in similar errors.
When using DSCP in Cisco IP Communicator 7.0.5 and after a PC reboot, the first call to the affected workstation experiences one way audio. This issue only occurs on the first call after a reboot and the subsequent calls are unaffected.
This issue is documented by Cisco bug ID CSCtl18743 (registered customers only) .
As a workaround, perform these steps:
If the user has elevated privileges, change the AudioQOSMode to 1 in order to enable GQoS, by creating the following registry value. Go to Start > Run and type regedit. Under HKCU/Software/Cisco Systems, Inc./Communicator, create a DWORD value AudioQOSMode and set the value to 1.
If the user does not have elevated privileges, disable the DSCP marking by creating the following registry value. Go to Start > Run and type regedit. Under HKCU/Software/Cisco Systems, Inc./Communicator, create a DWORD value AudioQOSMode and set the value to 0.
The Cisco IP Communicator gets stuck in a blank screen during startup because of a corrupted registry hive.
This issue is documented by Cisco bug ID CSCts11852 (registered customers only) . Refer to the bug for a possible fix and workaround.