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New Member

7920 Voice Problem

I am having problems with 1 way voice or no way voice on the 7920 models only and I can not figure it out. the Phone rings and Answers but nothing either way . I have no packet analyzer available at this time.

The phone registers via QIP DHCP with Option 150 and gets its DN.

single 3.3.3 latest patches

AP 1200

7960- Registers to CCM

7920- Registers to CCM

single subnet

No Firewall

7960-7960 works fine 7920-7960 works fine

7920-7920 phone rings you can answer call but nothing

7960-7920 phone rings you can answer call but nothing

You can here Tone on Hold no MOH. we are using 1.06 firmware on the 7920 with the ccm & Ip Phones on the same IP Subnet we and we are using 1 access point w/ LEAP no WEP and we authenticate sucesfully.


Pc to PC on the wireless works fine

Pc to 7920 works the way it should with !.!!.

Could it be the Vlans on the AP this is on a production network. We can Ping.

Any Ideas


Re: 7920 Voice Problem

Did you try the same setup without VLANs? If so, theRF will be fine. Make sure you don't have TKIP/MIC enabled on the VLAN as well.

New Member

Re: 7920 Voice Problem

There is a know bug for the problem you are having. The bug is CSCed52752:One-way audio happened at 7920 when it calls 7960 locally.


One-way audio happened at Wireless IP Phone 7920 when it calls CP-7960

hard phone.


Cisco CallManager 3.3(3) SR3

Cisco Wireless IP Phone 7920 Load 1.0(6)

Cisco IP Phone 7960 Load P00305000300



We have extactly the same problem with the load 1.06 on the 7920, and with the loads P00305000300 and P00305000400 on the 7940/60. We also get no way audio between 2 7920's. Our setup is identical to yours with regards voice vlan/subnets.

After some testing, the problem does not occur on these devices if the AP is left open or if the 7920/AP use static WEP Keys. Only seems to happen when we use LEAP, so must be related to LEAP.

We had the same problems when we downgraded the 7920 load to 1.05.



Cisco Employee

Re: 7920 Voice Problem

You can resolve this issue by enabling ARP caching on the AP.



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