We had a call from a long standing customer with a very strange issue - periodically they would get a recording in the middle of a phone call to their head office saying "your recording has finished". There were also intermittent double connections when calling other numbers too. Head office was also experiencing some voicemail weirdness with conversations having been partly recorded.
The site with problems is in Wooloowin and has an Avaya IP Office Rel 8.1 Essential Ed with 2 VoIP lines through World Dial Point and 3 Telstra PSTN lines. The Head Office in in Milton and has an Avaya BCM50 Rel 3 with ISDN20 Primary Rate ISDN and direct indial also with a couple of World Dial Point VoIP lines for outgoing calls. A thorough investigation was made of the VoIP lines at Woolloowin to check that call recording wasn't set up. World Dial Point were very helpful as usual and checked call records which showed no double connections.
I decided to turn Automatic Route Selection off and temporarily bypass using the VoIP lines for outgoing calls. A test call grabbed Line 3 which is Telstra and the call to the number ID robot gave me a readback of the line number plus a simultaneous readback of a line with a blocked number so that part of the mystery had been solved - Telstra line fault. Loop current was a giveaway at 80mA - well above the normal 30 to 35mA although all the lines seemed quite 'hot'.
I had to go to head office to install a couple more phones so I was able to investigate the voicemail weirdness and on the drive there the penny dropped: 2 calls were being originated from Wooloowin to the same indial number at Milton so the first call got through to the extension but the second call got forwarded on busy to voicemail. I checked the Class Of Service for the voicemail and found it is set up with a 5 minute limit for each message so when the call got to 5 minutes that's where the mystery recording came from.
ICS Technologies is located in Brisbane, Australia with national coverage on a variety of phone systems.