atcomsystems.ca/forum Forums Other TDM Phone Systems Vertical Telephones & Systems Vertical Summit Voicemail issue with SIP trunks

In January our customer called and said Calls were not going to voicemail. It is a Vertical Summit 80 equipped with SIP lines. We made a visit and found the following: 1. Calls sent to voicemail ring with no answer. 2. Log-in to check messages is good. 3. Leaving an "internal" message works. 4. Outside transferred lines (SIP) to Vmail rings with no answer. 5. We changed the call coverage to go straight to Vmail on external incoming calls. Still no answer.

Went back to our office with downloaded database from customer. Uploaded to our Summit 80 with analog lines and it worked. Unfortunately, we do not have SIP trunks. We decided to see if the analog line would work at the customer site. We installed an ATI unit from our VOIP system and connected the analog line. Calls made to the analog line and transferred to voicemail worked. Only SIP calls do not work. Talked with Vertical and we reset the voicemail and rebuilt the database. Also checked with the Sip provider and they said they have nothing to do with the call once it is answered. The local internet provider said the same. Also we were told no upgrades or changes were done on the circuits.

My question is, what could cause this to start in Jan (The Summit has been working great for about 10 years)? Why would it only be on the SIP Trunks? What could we be missing? Your suggestions would be greatly appreciated. Don't want to replace the unit then find out we still have an issue.

Vertical has historically had the ability to do a maintenance log trap to see call progression records. Press tech support to see if they have a debug backdoor to see what is failing.