anomaly0617
Member
- Joined
- Feb 9, 2012
- Messages
- 50
- Reaction score
- 11
Hi all,
If you've gotten here by searching for DIALSTATUS = CHANUNAVAIL and HANGUPCAUSE = 21, this is my experience with it and how we fixed it. YMMV.
I have a guy who is rarely at his desk, and as soon as we put the new phone on his desk he asked how to forward his calls to his mobile phone. Again, he said, he's rarely at his desk so while having a phone there is nice for the occasional support call or conference call, he just picks up all his calls on his mobile phone.
No problem - I walk him through *72 + [ExtNumber] + # and he's on his way.
That is, until they switched from a PRI line to SIP Trunks this past Tuesday.
Suddenly, his call forward stopped working. People were just getting his voicemail after one ring. In between opening a support ticket with the carrier (our ISP that provides dedicated SIP through fiber) and waiting on a response, I'm pounding my head against a wall trying to figure out what changed that would cause this to stop working.
I found it with the help of 4-6 hours of Google searching and reading every article I could find that remotely related to call forwarding and/or the above error.
Here's the problem: The SIP trunk provider will not accept a call with no caller ID. Normally, the caller ID is managed for us by either the Extension or the Outbound Route, both of which allow Susie in Company A to call out as Company A and Tommy in Company B to call out as Company B. But nope. That's not what is happening here. Here's what is actually happening:
A call comes in to Extension [Whatever]. Call Forwarding is enabled on that extension to a mobile phone, and whereas the logical assumption would be that Asterisk would go through the Outbound Routes top to bottom until it found the first match for this syntax [NXXNXXXXXX], it instead dives straight for the Trunk. The trunk has no Caller ID on it, so the ISP says "nope, not on my watch are you making a call without something, even if it's nothing" and they reject the call.
So to break down the errors above, DIALSTATUS is CHANUNAVAIL because none of the trunks are going to let that call out the door without a number and HANGUPCAUSE is 21 because 21 means "call rejected 403 Forbidden (+)"
Solution: Put in a default Caller ID in your Trunk. Then override it at the Extension level if necessary. But a default Caller ID in the Trunk is a requirement, apparently.
Again, just my experience, from our SIP carrier, and YMMV.
If you've gotten here by searching for DIALSTATUS = CHANUNAVAIL and HANGUPCAUSE = 21, this is my experience with it and how we fixed it. YMMV.
I have a guy who is rarely at his desk, and as soon as we put the new phone on his desk he asked how to forward his calls to his mobile phone. Again, he said, he's rarely at his desk so while having a phone there is nice for the occasional support call or conference call, he just picks up all his calls on his mobile phone.
No problem - I walk him through *72 + [ExtNumber] + # and he's on his way.
That is, until they switched from a PRI line to SIP Trunks this past Tuesday.
Suddenly, his call forward stopped working. People were just getting his voicemail after one ring. In between opening a support ticket with the carrier (our ISP that provides dedicated SIP through fiber) and waiting on a response, I'm pounding my head against a wall trying to figure out what changed that would cause this to stop working.
I found it with the help of 4-6 hours of Google searching and reading every article I could find that remotely related to call forwarding and/or the above error.
Here's the problem: The SIP trunk provider will not accept a call with no caller ID. Normally, the caller ID is managed for us by either the Extension or the Outbound Route, both of which allow Susie in Company A to call out as Company A and Tommy in Company B to call out as Company B. But nope. That's not what is happening here. Here's what is actually happening:
A call comes in to Extension [Whatever]. Call Forwarding is enabled on that extension to a mobile phone, and whereas the logical assumption would be that Asterisk would go through the Outbound Routes top to bottom until it found the first match for this syntax [NXXNXXXXXX], it instead dives straight for the Trunk. The trunk has no Caller ID on it, so the ISP says "nope, not on my watch are you making a call without something, even if it's nothing" and they reject the call.
So to break down the errors above, DIALSTATUS is CHANUNAVAIL because none of the trunks are going to let that call out the door without a number and HANGUPCAUSE is 21 because 21 means "call rejected 403 Forbidden (+)"
Solution: Put in a default Caller ID in your Trunk. Then override it at the Extension level if necessary. But a default Caller ID in the Trunk is a requirement, apparently.
Again, just my experience, from our SIP carrier, and YMMV.
Phone System 