Friday our SIP provider told us that they are receiving excessive re-invites from our Mitel system. This causes their SIP server to temporarily blacklist our IP address and all calls go silent (loss of audio) for 5 minutes.
This is a new install and this problem has been happening since day 1 and we were very shocked just to be hearing about this now. However, the carrier says this is being caused by the Mitel System.
The system is 8.0 SP1 using MBG 10.0.3.14. The general call flow is as follows - SIP calls come in and traverse across a WAN to a Call Director Mailbox for a schedule and plays a greeting with 2 options. Once you make a choice the calls transfer to an ACD group back on the Local LAN (local to SIP trunks) that contains three different RAD Greetings (embedded VM). Calls hold until answered. Nothing out of the normal. Calls on hold range from 10-50 minutes as a rule. When this problem was identified recently there were 10 calls on hold with an average hold time of 6 minutes.
Question - has anyone ever experienced what is described as excessive re-invites or a carrier that blocks an IP address because of this problem.
