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No Voice in 7940 Ip Phones

Hi i have just installed ccm 4.1.2. I successfully registered 3 ip phones


Tftp sever is pulling all three files from ip phones and getting registered in ccm. All the phones in ccm is registered and showing ip addresses of each phone.


1. Call manager Ip Address: Location Florida- Using Pix 520-Public Ip port forwarding to ccm(port 69 and 2000)

2. 7940 ip address Location miami - No VPN Tunnel

3. 7940 ip address Chicago - No VPN Tunnel

4. 30 Vip ip address Location arizona - No VPN Tunnel

Above three phones are in different location as you can see above subnet.

=> From 1 i can call 2 and vice versa. Both can receive and make calls but cant hear voice.

=> From 1 and 2 unable to make and receive calls to 3 or from 3 unable to make and receive calls.


Please advise.


Re: No Voice in 7940 Ip Phones

Hi There,

First step, you are going to need to do some basic connectivity testing between the phones. i.e. plug some pc's in and make sure you can ping between all the phone subnets.

When you say no vpn tunnel? Are they private links? How are they connected?

You are going to need udp RTP traffic at the least between the phone subnets also.

I would look at your network infrastructure thoroughly first. VPN tunnels with QoS may be more appropriate if you are using the internet instead of a private or managed WAN.



New Member

Re: No Voice in 7940 Ip Phones

Thanks for emailing. Yes i can ping the phones from PC.

All the phones connected in three diffrent homes.


If you have any ip phones in your office or home. I can provide you my ccm tftp server address. Once you input the tftp address in your ipphone that phone will automatically registered in my ccm and you will be allocated an extension number. That means your phone is registering in my ccm but when you ring my extension 1004 or 1002 or 1003 its ringing but no voice.

Please provide your email address i will send you my tftp address. Thanks for help


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