atcomsystems.ca/forum Forums TDM Business Telephone Systems Avaya - Lucent Telephones & Systems Long call times/Avaya Aura/800 number

So I've been asked my opinion on a weird issue a customer is haveing. They have a 800 number that points to an auto attendant, that routes calls to different locations, or to a mailbox, depending on what they choose. Every month they're getting about 6-10 calls from all over the country that stay online for exactly 512 minutes. It seems like there is a disconnect issue and calls are stuck in a loop or something. Funny thing is, it's at odd hours, not usually during normal business hours. I've checked into toll fraud, they do have trunk to trunk transfer on, but there are no outbound long distance calls at that time. Also, most of the calls appear to be either cell numbers or SIP trunks. Any ideas?