I have an IP office 500 that i set up a phantom extension on and it is set to unconditionally foward a call to a advertising agency then they return the call back to IPO. This works fine when i dial the phantom extension internally but when an external call comes in and hit incoming call route destination phantom ext it rings busy. My telco service is windstream SIP. Calls through windstrean network works but i call in from my cell phone i get a fast busy. My thought is windstream is blocking outbound because of the number of ditits (10) it is recieving then blocking. Any ideas?