Cisco 7960 Button Delay/Latency

Hello, I’m looking for some ideas on a problem with Cisco 7960 phones that I’ve been researching for a while now. I’ve searched these forums as well as others and haven’t been able to find similar symptoms. I’m running an ACD environment with FreePBX 5.211.65-14 and Asterisk 11.12.

The issue is that intermittently there is a delay in response from the 7960s when pressing buttons. Most of the time this is noticed when dialing an outbound phone call or entering feature codes, however I’ve been able to recreate it without an active call being present (e.g. delay when entering password to unlock config). Usually when this issue occurs it takes about 10-15 seconds for the phone to catch up after a button is pressed.

This is happening on all 12 connected phones. I suspect firmware, but I’m running 8.12, which seems to be the most common stable version.

Thanks in advance. Please let me know if I can provide any further details.

I experience a similar issue on our Polycom phones from time to time, but not nearly as severe of a delay…so far I have 0 solutions and I suspect firmware issues as well.