low voice problem- upgrade

[lapakhora]

Hi,
Customer is asking for a low voice problem after an upgrade of system from release 3.0 to 7.6, Specially when a call initiate using COT line. Further when caller getting broken callpilot greeting (some words of auto attendant greeting gets missed or broke) when the call in through COT line..callpilot also upgraded to release 5 and it is on 202i.
Any help??

Regards..

 

[KCFLHRC]

What type of system, chassis, cabinet, what ?????

 

[lapakhora]

it is CS1K, cabinet system with CPMG.