We have tryed 2 M 7324 sets, version 12 on an MICS with version R1/T1.
We are getting the volume dropping off during calls. Anyideas why?

Are lines POTS are T1?

Lines are all POTS.

Put one or two 2500 sets at the desk where the issue is happening..probably the receptionist. When the volume drops off when on a Norstar set have them pick up the 2500 set to see if they have low volume. If these sets are hooked up to the CO lines before the system and the single lines have low volume you are looking at a line issue. Loud volume=system issue.