NO JOY Calls to transcription service dropping.

[just_some_random_dud]

I have a medical practice that still uses a transcription service. The doctors call in and speak to a voicemail type system. Recently the calls have started to drop every time. Could this possibly be some sort of timeout feature on the pbx that is dropping the call after a period of silence from the remote party? And if so is there a way to fix this?