Low voice (incoming voice) on BCM400 through COT lines

[farazmangal]

Hi all, need your help in this...
We have installed a new BCM 400 with latest patches at a site, before this BCM they were using Norstar MICS. We are using old Norstar set and some new T series sets with this BCM. Old Norstar series (M series) sets were working OK with MICS but when a call comes through PSTN(COT, GATM card) on these M series set we get low noise of caller, the outgoing voice is OK on COT lines through these se. Please also note that calls from ISDN PRI to these M series sets is OK, both outgoing and incoming voice is OK but when a call comes from COT we get low noise on these sets. T series sets are working fine...Any help whether some GATM card required some settings or something else??
Thanks and regards.

 

[Dasheen]

Some m series aren't compatible w/ BCM. What rls are the sets? I believe the sets need to be above rls 16. Any lower and u have volume issues.