NEC Aspire Phone system on a T1 PRI worked great for 2 years.
Changed to Cablevision SIP Trunk and then started to have problems with outbound and inbound calls.
Dialing out takes 7 seconds before you hear the dialing when it works and if not the call still goes through to the customer, but they have dead silence on their end.

When this happens you don’t hear any dialing out but the customer thinks that they received a prank call. Many times you have to dial 3 or 4 times to get out and it

seems to get worse as the day goes on. Usually we do a redial and then the dialing starts right away.
To work around the problem I usually have to reboot the Edgewater Sip Trunk Adapter or pull the T1 card out of the phone system.
The phones start to work again, but still take 7 seconds to hear the outbound dialing, but as time goes by and we make and receive more phone calls the problem

gets worse and I have to reboot the Edgewater or pull the T1 card. Our customers are emailing us saying they are getting a fast busy when they try to call us.

Cablevision has not been able to fix the problem and is pointing fingers to our PBX.Our phone system provider is blaming Cablevision's Sip Trunk adapter/service.