Hi,
I have a serious problem with Cisco SPA525G2 (40 phones). I have tested those phones with asterisk 1.4.30 and 1.6.2.17 both installed in VMWARE ESXi. Firmware on the phone 7.4.5, 7.4.7, 7.4.8. Tested with codec g711 and g729. SIP and RTP ports are opened on the firewall. In general audio quality is very poor comparing to Cisco 7911G and Cisco 7965G ( to much bass). Additional audio gets crackly after few seconds of conversation. Which is biggest issue. We also experience audio issue which sounds like VAD enabled but it is not (or push to talk conversation). We have Cisco 7911, 7921, 7965 connected to the same PBX and there is no issue with them what so ever. I wonder if you could give us some clue as it is matter of urgency, please?
Update:
I managed to much bass on the phone by disbaling Deep_bass option as described here:
https://supportforums.cisco.com/docs/DOC-10012
Please advise on this issue.
Best Regards,
Konrad