Has anyone ever experienced random "clicking" noise in the IP phone (7940/7960, firmware: 7.2(4.0)) on inbound calls? I've upgraded the Cisco 2821 IOS from Upgrade IOS from c2800nm-spservicesk9-mz.124-2.T2.bin (18-Oct-05) to c2800nm-spservicesk9-mz.124-15.T1.bin (18-Jul-07) as suggested by TAC, but it still didn't resolve the issue.
I've checked the controllers, and they're clean. Jitters are within limits (20ms-50ms), Rx and Tx are 20ms.
The strange thing is that the clicking noise is randomly happening in our Call Center, no where else in our company is experiencing the same problem...
Any suggestion to troubleshoot this issue is greatly appreciated.