atcomsystems.ca/forum Forums VOIP Phones & IP PBX VoIP & Cloud Phones, Hosted PBX, General IP Phones SIP trunks not disconnecting

We just installed a new MBX with SIP trunking. Everything is finally up and running after a bit of head-banging and troubleshooting. Now the only issue that seems to be remaining is that the SIP trunk doesn't seem to disconnect. If you make a test call into the system and then just hang up, the trunk stays online and even rolls into voice mail and records dead air for a while. Not sure if this issue is us, or the SIP provider??

Who is the carrier? A Certified SIP provider by Vertical?

Call me crazy here, but isn't SIP supposed to be a uniform signaling standard, like those with ISDN-PRI, loop-start, ground-start, etc?

You know, those pesky little rules that have been around for decades.

Should there be any difference between service providers if they are providing a uniform service? Does the FCC oversee SIP trunking standards? My own questions are starting to scare me.

Never mind. VoIP apparently has its own set of standards. I'll be glad when those of us on the front lines are afforded knowledge of the new set of standards. This is getting downright silly.

Its not a registered carrier with Vertical, but I agree with Ed. Aren't the standards supposed to be uniform?

It would be my guess that since Vertical has a list of tested carriers, variables do exist. And remember, we still fight with carriers who don't automatically provide loop disconnect. Regional carriers and even Comcast drive me up a wall at times on that one.

Every SIP provider is a little different. Sounds like you have a programming issue. Who is the provider? PM it to me if you don't want to name them.

I've seen routers cause issues like this (turn off any SIP ALG), or lack of port forwarding (5060 UDP + RTP ports pointed to PBX IP).

Alot of providers do authentication in different ways hence the problems. You might be able to make it work with trial and error but Vertical will not waste time trying to reverse engineer every provider in the field...that's why they have an approved list.

Should the carrier be providing some type of disconnect? That would make the most sense, but what types of disconnect are standard? I am trying to get ahold of the engineer for the carrier tomorrow. I have been trying to do this while I have been out of town.

Standard for Loop start is a 1/2 second loop open from the C.O. when the distant party hangs up the phone, releases their line/trunk, whatever you want to call it. Ground start, the C.O. lifts the ground as a signal (And permanent release) that the distant party hung up.