[asterisk-users] Phantom Rings

[Lee Jenkins]

Brent Davidson wrote:
> I'm having a major problem at one of my branch offices with "Phantom 
> Rings" on their asterisk-based phone system.  The system was originally 
> built using 2 X100P cards and was recently upgraded to a Rhino R4FXO-EC 
> card.  The upgrade severely increased the frequency of the phantom 
> rings.  I've read everything I can find on-line about automatic testing 
> and noise on the line and have made several calls to Verizon with no 
> solution to the problem.  I know the telco switch that is feeding my 
> analog lines is an old switch and can't even do CallerID with 2 lines in 
> a rollover configuration.  Audio quality on the line is perfect during 
> voice calls.  No static or other noise.  I've asked for disconnect 
> supervision to be added to the line, but It doesn't look like it's 
> there.  The line still seems to keep the channel open long after the far 
> end hangs up.
> 
> Has anyone else ever seen this problem or have any ideas how to 
> eliminate it?
> 

Brent,

I had a similar problem and I feel for you, its frustrating.

Are you using polycom phones by chance?  Here is the problem that I had, not 
sure if your problem is related.

Specs:

- 6 Polycom 301 phones.
- CentOS 4 Server with Asterisk 1.2.x
- Sangoma A200 card with 3 FXO ports.

Pretty simple settings for a small office where a group ring between all 6 
polycoms was initiated once the call was received.  After that it would go to a 
auto attendant and give the caller option to continue to hold, leave a message, etc.

At any rate, once in a while, Caller ID would fail, either on the Sangoma card 
or somewhere in Asterisk, not sure, but CLI clearly showed an error on caller ID 
every once in a while when a POTS call came in.

All six polycoms would ring, but when you picked up the handset or hit the 
Answer soft button, nothing would happen, you couldn't answer the call.  The 
phones would just ring, and ring and ring for the duration of the group ring 
(about 60) and the customer was really annoyed since it was a small office.

Continuing, the problem finally turned out to be the polycoms!  When no caller 
ID information was present, the polycoms wigged out and while they did ring, you 
could not get the phones to pick up.

I could readily replicate the behavior by initiating a Call File without 
specifying the caller ID information using the local channel.  It would happen 
every time.  Specifying the CID would allow the polycoms to work correctly.

On the customer side, I did a quick GoToIf in their dialplan to see if the 
caller id info was set and if it wasn't I would set it manually to something like:

CALLERID(num)=555-555-5555
CALLERID(name)=CID FAILURE


That cleared up the problem.

HIH

--
Warm Regards,

Lee