sundance-communications.com/forum Forums General General Telephone & Systems Information Loop start trouble

Have a customer that switched from Verizon to a CLEC for dial tone. Ever since this change we are getting a strange problem with one of the trunks. The problem only shows up when connected to the key system but is fine when tested with a butt set.
Here's description of problem.
a) I dial the trunk. b) key systems shows line as busy while I hear ringing c) key system trunk goes dead d) rollover takes place and next line in rollover hunt starts to ring on key system.
We've moved the troublesome trunk to another port on the key system & the problem follows the trunk--so we don't think it's the key system. Verizon & CLEC were both out & insist the line is fine.
Glad for any help. I'm thinking its an electrical problem such as low loop current or low ring voltage etc. Never saw a case like this before.

If you moved it and trouble follows fine...then there is no thinking it's not the key system, you have proven it's the trunk. Tell them to find the problem...the CO or provider.

Problem is, I've already told them "It's your problem--go fix it" with no results from the repair tickets that were placed.
Sometimes it's easier to fix a telco problem yourself then get them to do it. Only problem is you have to know how to diagnose the problem.

We can fix that problem, by talking about them in the Hall of Shame, and send the link to one of the higher ups in that company...Gets results.

Is this a T1 with a channel bank? Check your ring voltage. We've had the same problem on occasion. CLEC does not want to fix it because it rings the tech's but set just fine. check the ringing voltage. Our problems starts when it drops below 53VAC.

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Split cable pair maybe? So I assume when you dial the 2nd line everything works ok. You say problem follows on different line port on key system, is it just a port or do you have features built into the port? If you have features, just put it on a plain jane co port and see what happens. I can see where telco would be confused if it only happens when hooked to the key system. When you dial the ANI from the cable pair what do you get?

a) I dial the trunk. b) key systems shows line as busy while I hear ringing...

I'm a little confused with (b). How would the key system show the line as busy? I would expect the system either to do nothing or ring if there were a problem on the CO side. If it shows that the line is busy (in use) something has to be taking that line off hook on your side as soon as it starts to ring. Because of the speed it looks like a ring-trip problem. Does this trunk ring anywhere the next trunk in the hunt doesn't?

To make this even more confusing it looks like the trunk is acting weird by busying out too soon and rolling the call to the next number in the hunt.

-Hal

It sounds like an open tip side of pair, or power on the line. Monitor line with butt set, and heck the voltages on the line.

Have same trouble with Verizon at one of my customers that are at the max distance from CO. It is always there problem, but they will not fix till we request a Telco meet.

Good Luck!!

I feel your pain. This is dificult to diagnose without knowing the co facilities. If this was just a co switch port (OE) to cable pair to you, you could ask for an oe cut on suspecion. In the circuit there could be MFT's, pairgain, D4 carrer. Your CLEC could be a reseler and all of the equipment could be VERIZON. any of this equipment could cause this problem.

Here is whats happening. A buttset is a dry circuit. There is no grounds, shorts or battery on the tip and ring. The PBX places resistive battery or ground on the tip and ring to see if the line is there or open. The co equipment uses differant circuitry to detect an off hook during ringing than when the line is idle or talking. The OE see the line as idle. When ringing is applied the oe sees the line as off hook. The oe switches to talking and sees an on hook again. CO programing sees this as not normal and removes the line for testing. CO roles the call to the next line. PBX sees the line as open during testing and makes it busy.

This is my two cents

Had same situation when a customer changed to MCI through their bulk buying system. It had each CO set as if it were Centrex with each CO bsy/na in rotary then to MCI VM. Customer neglected to tell MCI it was going into a system. Three rings and the call would jump to the next CO. If she hit it after the third ring, the system showed busy. Drove the recptionist nuts trying to grab the next line! ! ! It took MCI two weeks to reprogram.

[This message has been edited by KLD (edited April 08, 2005).]