Phantom trunk ringing.

[telecomtekperson]

Customer has IPOfc 500, R4.20 and a 16 port analog POTS line card. They are using 14 POTS lines for inbound/outbound and the calls ring IN into a hunt group of 3-5 phones. Recently, they have been receiving PHANTOM CALLS that continue in 5 second intervals and don’t stop until that line is removed from the hunt group. The display on the phone shows the name of the hunt group but no caller ID appears and when you pick up, there is nothing there and the ringing stops for a moment and when you hang up, it continues within 5-10 seconds. I was watching in Monitor and had it narrowed down to two ports, Lines 2 and 4, so since there were two available ports, I moved the lines to them and programmed accordingly and problem solved. I was there two days later to change one minor issue and when I was there, the phantom ringing began again…….this time on Line 3.
I did an upgrade to 4.23 and as soon as I was finished, the phantom ringing began again on Line 3. I took that line out of the inbound call group just to make it stop, but obviously that can only be a temporary fix.

When I clip on any of the lines at the 66block, I get no phantom ringing, with/without line plugged into Line Card. I can call out fine and receive calls fine on my butt-set.

Does this appear to be hardware?

Thanks in advance.

 

[Delmar]

I have had this problem before and it turned out to be high loop current.
Loop current should read around 25MA for CO lines.
On the system I was working on current was over 45MA and I was getting intermittent phantom ringing.
I put some loop current attenuators in series with the line and that cured the problem.
You can get some attenuators that fit right on the 66 block from Mike Sandman's website.
Look at the line field in system status and see what lines have a large number of abandoned calls. Those are most likely the lines affected if this is the problem.

 

[nlasch]

Do phones have lines appearances AND the incoming calls are going to a huntgroup the user is a member of?

You can't present the same call to the phone from two different appearance buttons or the phone gets confused.

Either a) have the line appearance not ring on the phone or b) disable their membership to the huntgroup (keep them in the huntgroup but uncheck their name in the list)

 

[liquidshokk]

One of our customers is also having this problem, but they have BRI lines. The huntgroup rings, they pick it up and hear silence but then it continues to ring whey put it down.

nlasch, read your post a few times but i cant understant what you mean. could you rephrase please?