Hello folks, I would like to pick your brain about some phone line issues on a fire panel at a school. Have no idea what brand it is becasue I'm just a lowly telco tech. The customer kept reporting issues on Line 2, but all my tests indicate no trouble on the line. So we reversed the L1 and L2 at the demarc. The next day they are reporting trouble on L1 which is the same telephone number that was feeding L2 the day before. I have changed pairs on my end and rebonded every splice I can find. The alarm guys have changed parts including dialers to no avail. I have verified this number is not shared by any other CPE. Anyone have a suggestion on what to do next. Don't know much about the fire alarm industry, but I was wondering if a dedicated fire line receives a call, does it go into trouble mode even if no one answers it? Since this is a new business I'm wondering if the number assigned belonged to someone else and people keep trying to call it?

who is providing the DT ?

have you looked at loop current ?

It is AT&T local. I have 23ma of loop current

I doubt it is because the call is not being answered. I know that you said you have verified that there is no CPE shared on the line, but are you really sure of this? The only guaranteed way to provide this is with an RJ31X jack. I'm not doubting your intelligence, but every (I mean every) time I've encountered this, we have found some bootleg connection somewhere. When it goes off-hook to use the line, the alarm system detects this as a line trouble since it isn't officially on the output side of the alarm dialer.

I chased one of these for two months at a high school. We eventually determined that there was a multiple of the F2 count that appeared at an outbuilding on the property. Yep, that same pair was appearing on an unused jack there and someone was using it as their fax line. They thought they were getting free dial tone. Since it was bridged ahead of the alarm dialer, each time the line was seized by the rouge fax, the alarm system detected the line voltage drop as a fault and reported it accordingly.

In your case, an F2 issue isn't likely, but have you physically verified that nobody has tapped this line up in the ceiling somewhere? Don't ask anyone to give you a truthful answer since they probably won't tell or they just don't know.

Oh, and

We aren't as dumb as we look!

Sorry Ed, but I just can't resist - those pretty pink fax machines have always given me the most problems too. But to your credit, those ugly beige rogue ones can be difficult to find.

The panel is fed by a 4pr Cat5e that runs 40ft from the demarc to the panel and every inch of the wire run is visible. I tested the OSP side and looked for foreign ringers and bridged tap and there is none. I am almost convinced this place is built on an ancient indian burial ground or something. As a tech it is getting hard to face this customer because I'm pretty sure they have lost faith in my ability and won't believe anything I say.

whats the loop current on the line that works ?

have you tried putting the problem line on a different pair ?

I would also compare polarity with the line thats working

The voice grade parameters are exactly the saem as the other fire panel line that never shows trouble. I have changed F2 pairs 4 times, F1 pairs 4 times, changed pair gain cards in the RT and CO, and we even ran a #4 ground wire into 4 manholes and I bonded the cable sheath and splice case to the ground wire. Polarity has been checked. All POTS at this address show 23-26ma.

Hello,
What type of switch is this being serviced out of? Is it coming off of a remote terminal? Have you replaced the line card supplying dial tone? I have seen bad line cards from an RT cause this, the card just dumps dt for a few minutes then comes back up. Maybe have your switch tech move it to a new oe???

...or have them replace L1 with a ul certified cellular dialer :rolleyes:

Line cards have been changed and the pair has been moved to different cards and different shelves.

So what are the "issues" that the panel is reporting?

Loss of Dial Tone, or Communication Error?

Had a burglar alarm which was fed on the return of the fire alarm's secondary dial tone, which could not communicate. Using a Sidekick, on the stress setting, saw a HUGE difference between the Telco side and the return from the fire alarm. Luckily, they had a copper Fax line that they could move the burglar alarm to, and leave the fire alarm with both lines dedicated.

The monitoring company reports "noise on line". The building occupants report the panel giving audible noises, but it has not resulted in a fire department dispatch. I really wanted to say the trouble was in the panel, but my trouble followed my from the L2 position to L1 when I swapped the pairs.

have you only tested the pair at the NID?? or have you tested it at rj31x before the panel? Sorry if these questions sound basic..just trying to cover everything and anything. Does this come from an RT, like an access node or pair gain or is it straight copper? If so check the T1's feeding the RT for errors. I have seen where these T1's will take timing errors and some slips, voice calls will be fine, maybe an occasional click but it kills data.

I have tested the lines at the jack inside the panel, but they are just RJ45. The service originates from a fiber fed digital pair gain RT and there is about 3500ft foot of 6 month old copper feeding the building. I thought it could be an RT issue, but this address has another line that never reports trouble and the only thing the RT feeds is a medical center, a hospital, and two college campuses, each with dedicated fire alarm lines and none of them have ever generated a trouble report. The only thing I am left to wonder about is that something is tripping the 48vdc that the panel is looking for. The only thing I don't know is who had this phone number prior. Tomorrow I am going to hook a stand alone caller id unit to the line and let it site to see if that number takes any incoming calls. Because at this point that is the only scenario that could be causing the voltage to drop. Thanks for all the replies so far.

Please let us know how this turns out.

Oh boy, I can't believe I did that! I'm going to have to start spell-checking my spell checker in the future. Doh!

I'll tell you one thing, Campinfool, you've sure done a lot more than most telco techs would do. I admire your dedication to this and to your customer. I must say that in reading your progress, I can't see how the problem could possibly be in the phone line itself. These systems really aren't that sensitive, so my money is on the alarm dialer having an intermittent fault.

I went out today and replaced the 22awg jumper wire feeding the demarc with 24awg wire and changed pairs in the iw running from the demarc to the rj45 feeding the panel. Of course when I'm there the lines show no trouble. I did test my incoming ringing current test to see if that was triggering the errors, but it failed miserably. I have thrown everything in my arsenal at this thing, but the customer still tells of trouble. I'm out of ideas, the customer wants a special engineer to come back out for testing, but when he was brought in in December he told us that everything was up to standards even though the customer does not quite remember it the same way.
After 4 trips this week alone the customer told me he wants someone else to fix the trouble because I have not been able to. Good luck to the next guy cause there is nothing wrong with the service on the telco side.

I HAVE TO AGREE THIS IS NOT A TEL CO ISSUE. THAT DIALER NEEDS TO BE REPLACED

Problem is the dialer was just replaced on Monday.

I am at a loss the only thing that almost makes sense is an intermittemt RT trouble but if both lines are feed from the same RT that is out.

Has a switch tech looked at it? Just to status the line...see if its going PLO or HW AUTO depending on your switch? , maybe blkd rt auto if its a 5e..

Make sure the in and out pairs on the RJ31X aren't reversed.

There is no RJ31X, just an RJ45. These pairs go straight to panel and nothing else is tied in.

So

• it is a dedicated CO line.
• it is terminated on a RJ45 Jack.
• it is connected from the RJ45 Jack to the panel by the means of a manufactured 8 conductor patch cord.

A few questions that come to mind...

• Has the patch cord been replaced?
• Has the RJ45 jack been replaced.
• What is the condition of the pins on the FA Panel side of the patch cord?

There has been many times I have seen faulty modular clips {especially those made in the field}, or even someone using a 6 pin base cord in an 8 conductor jack, and also problems with the pins on the jacks...bent pins, corrosion, foreign material, et cetera...

Remember: "Entities must not be multiplied beyond necessity"- Occam's razor

"How often have I said to you that when you have eliminated the impossible, whatever remains, however improbable, must be the truth?" -Sherlock Holmes

Keep It Simple.

Okay here is the resolution. The customer finally told me " we would like some one else to fix it" and muttered several 4 letter words about me in general. I turned this issue over to my manager who then escalated it up the chain of command in my company. Basically my area manager told the customer in so many words to have their fire panel vendor fix it or find a new voice provider because we have done every thing in our power to appease the customer. We even had a special design engineer from out of town come down to verify my original test that the line meet or exceeded voice grade parameters. I'd like to thank everyone for their replies and attempting to help me out.

Thanks for the update. I felt you went FAR above and beyond what is required.

Sure is nice when the 'Boss' stands behind you to back you up. Rather than to throw you to the lions!

Just curious was the Fire Alarm set up for first rights? I seen a lot of Fire Alarm guys T-tap the line. The fire alarm guys just don't have a clue when it comes to dial tone. Somebody might have all ready asked this.


Kinda sounds like they may have had some voltage running through that alarm system.