FXS analog phones causing Unity to continuously record silent messages

[jbouwkamp]

I have a customer with an ICS7750. 16 FXS stations are running on 2 MRPs with MGCP. Once or twice a week an analog phone on the MRPs will start leaving messages over and over again with nothing recorded for the operator station (which is using a 7960). You can see 2 of the ports on unity are in seized and in use for leaving these blank messages but the analog phone that is supposedly originating the messages works fine and can make calls. Very weird problem and I can't seem to think of anything that would cause this, has anyone else ran into a similar problem?

[irisrios]

Hope this is not the case when a caller who calls in and finds that the calls has reached Voice Mail and he just hangs up, because he decides not to leave a message for them. The Unity afer 2 seconds of silence will hangup. Such a case has already happened. Did you check if this is the same case?

[ibutterw]

Are you using g729 codec? If so it could be a known bug with mgcp not negotiating correct packet sizes for Unity. Try setting the preferred g729 packet size service parameter to 20 on Call Manager if it is set to something else. Unity TSP will only allow 20 byte packet size for g729.