7935-conference phone

Unanswered Question
Nov 24th, 2008


I have a 7935 conference phone registered with my call manager 5.3 version. It is working fine for the past 1 year. Suddenly it got disconnected from my controller and the ip phone keeps on rebooting. The dhcp address given to the voice network is 172.16.x.x but I can find (in call manager) the 7935 getting ip address 10.4.X.X.which is no where (dhcp) in my network. I am not able to add ip address manually. The 7935 is not able to take manually configuration, it is kept on rebooting. I can find in the display obtaining ip address…and then it reboot with a sound. Even I tried it by connecting in different ports.

please help...

I have this problem too.
0 votes
  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 0 (0 ratings)
rob.huffman Tue, 11/25/2008 - 11:05

Hi Satya,

This is a known issue with the Cisco 793x Conference phones. The clip below references the problem and fix;

The 7935 IP Conference Phone Receives Data IP Address Instead of Voice IP Address

If the 7935 IP Conference Phone is connected to a switch, the conference phone receives the IP address from the data VLAN. If the 7960 IP Phone is connected on the same switch port as the 7935 IP Conference Phone, the 7960 receives the IP address on the voice VLAN.

This issue is due to the design of the 7935 IP Conference Phones. This conference phone does not have a 10/100 port to connect a PC like other 7900 Series IP Phones have. The concept of voice VLAN or auxiliary VLAN does not directly apply to the 7935 IP Conference Phones


7935 IP Conference Phone Optimal Performance Configuration


Hope this helps!


rcrumm_2 Tue, 11/25/2008 - 22:06

Sounds like you have a rogue DHCP server somewhere. I suggest using a sniffer and taking a look.


satyamothukuri Wed, 11/26/2008 - 23:15


i am not using a poe switch.7935 is connected by using a power adaptor.If i connect to poe switch 7935 is not getting power.I heard that 7935 phone will have different cables(stright/patch cards)to connect,is it?

rob.huffman Sat, 11/29/2008 - 07:59

Hi Satya,

You are right using the power cube that is supplied with the 7935 :) There are no PoE Switches that can supply enough power for the 7935 or 7936 phones. I would have a look at your switchport config. Because the 7935 does not recognize the Voice Vlan command you must use;

switchport mode access

switchport access vlan xxx (where xxx is your voice vlan)

Hope this helps!


satyamothukuri Sun, 11/30/2008 - 21:38

Hi Rob,

I already done this but,no result.Do you think my FIRMWARE was gone....





This Discussion