Voice Issue: IP Phone 7911g cannot communicate with callmanager 7....help

Please can you help me with this voice issue;I have an issue on ground. We have 50 pcs of 7911 phones and 7946 Ip phones, we run on call manager 7.0 platform that perfectly operates our 7946 IP phones. We want it to operate and intercommunicate with the  7911 IP phones because it's not communicating with it and the 7946 IP Phones is working perfectly with it on the same network.

Please help me ....Awaits your quick response for action.


  • Hello,


    Are the phones registered at all? If so, what is the exact issue that you are having? This could be caused by many factors. Please provide as much information as possible so that we can assist with your issue.


    Thank You

  • Hai,

    the 7946 are working fine but the 7911g are not registered at all and am even thinking maybe callmanger 7 support 7911 or we need to upgrade some firmware or wat, please i need to know to do to make it work e.g configuration, upgrade or add smthg new...please let me know asap.

  • Hello,


    CUCM 7 does in fact support the 7911, however it is possible that you could be experiencing a networking or hardware related issue that is preventing the registration. Use this link to check for compatibie firmwares with the 7911G and CUCM 7+ http://www.cisco.com/en/US/docs/voice_ip_comm/cucm/compat/ccmcompmatr.html#wp52403

    Are you using auto-registration or manually registering the phones? If you are using auto-registration, try to manually register a phone using the mac-address. Also check to ensure that the phone can be pinged from the CUCM server.

  • Hello,

    i have added the mac-address manually to the callmananger 7 by checking the phone mac-address thru the phone settings...and i try to ping and is still not reply the echo, please i really need help on this issue, please help the possible cause n all. Thanks

  • Let's start with basic stuff - verify cable or phone; replace cable, try another phone; if it doesn't work try the following:

    Lack of ICMP reply suggest issue with L2 or L3, so verify that phone is in correct VLAN (remember that CDP provide with information about voice VLAN if this vlan is configured), verify switch port configuration (porfast, access vs trunk, speed, duplex). In relation to L3 - do you have IP address from DHCP (default) assigned to this phone? Do
    you have option 66 or 150 (TFTP) configured on DHCP server? If the phone is in different VLAN than CUCM server, do you have routing between VLAN enabled and both devices have proper default gateways assigned.

    If you wish to exclude DHCP from the process, you can setup static IP address, static TFTP/CUCM settings (address)



  • As Seba said, if you cannot ping the phone, the issue is not with Call Manager, but instead a networking issue. Can you see the phone connected to the switchport using show cdp neighbors?

  • Hello when issue Cdp command, i can see the IP Phones and i can ping nw....but its not to be communicating e.g to dial out, or to recieve call.please help

  • Where are you able to ping from? The call manager server, or just the gateway the phone is using for IP traffic? If you can ping from the CUCM, ensure that the firmware is  compatible with the phone model you have, using the link in the post above.


    If you have the correct firmware, watch the phone while it attempts to register to see if any error messages come up.

  • i can ping from the CUCM to the phone nw, and to the gateway but i think the firmware is not compatible, please must the phone firmware be compatible with the one on the phone for it to support CUCM7, please kindly direct me on how to download a firmware that's compatible with CUCM7. Thanks

  • Rammany,



    Use this link to determine if the firware is compatible -> http://www.cisco.com/en/US/docs/voice_ip_comm/cucm/compat/ccmcompmatr.html#wp52403


    If you need new firmware, you must dowload it from the Cisco support downloads section, which requires a valid cisco CCO account.

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