When an old Stromberg KSU system that was installed many years ago at the church I attend started to act its age, I replaced it with (4) AT&T 944 sets.
Users started to notice an audible whine in the background of some calls. Replacement sets didn't resolve the problem. Staff complained about the poor audio quality of the messages left on an AT&T 1726 answering machine.
Ended up trashing the answering machine and telephone units and installed an Avaya Partner ACS R6 along with an Avaya Partner Messaging voicemail.
Expanded the Partner ACS system a few times so now we have a fine telephone/intercom system with no regrets about the upgrade!
