Signal format on US (Pacific Bell) phone lines 1

[spikeychappie]

I recently got connected up to PacBell and only get 24K internet connection speed. There is a multiplexer between the incoming phone line and my home wiring (I have two phone lines in the house) and I thought maybe this conversion stage was slowing the connection. As a test I bared the connectors of two cores (blue and blue/white)of the incoming cable and connected my phone direct into these cores to see if I could get a dial tone. I got no dial tone - instead I got a rather load mushy noise that I guess was digital in nature. On disconnecting the lines I got a nasty shock and when I tested between the two cores I measured 125V DC !! Can anyone direct me to some technical info that explains what is going on and whether there is any hope of improving my connection speed?

 

[vaoldschl]

You would have to explain to me what this 'multiplexer' looks like before I could answer the question, I think you are referring to the NID but I can't be certain. Do you subscribe to a digital telephone service or do you just have POTS lines. If POTS I should be able to help you out.

 

[spikeychappie]

The "multiplexer" is a box about 6" by 6" by 2". The incoming cable bundle (plus an earth) connects into the box behind a tamperproof cover. There are two sockets on the box which normally have the house phone lines plugged into them. You can remove a plug from one of these sockets and plug a phone direct into it. I guess you would do this if you had a problem and wanted to know if it was the house wiring or the telephone company wiring. The two sockets are marked Line 1 and Line 2. There are some LEDs on the side of the box (I can't see what they are marked). I call it a multiplexer because the guy who installed it told me that only two cores of the incoming bundle were connected up, and the box splits it into two phone lines for the house.
I don't subscribe to a digital phone service, so I guess I must be on POTS.

 

[vaoldschl]

Okay, sounds like a NID, but your assessment is probably closer to the truth if they are using a single pair to provide two phone lines. That's what you see, right? Off the wire coming to the box from the pole there is only a single pair (white/blue-blue/white if I read you correctly)connected?

Question, why didn't you use the test jacks provided in the customer access section to connect directly to your modem and check the speed of connect? That would isolate the problem as either internal to your house or somewhere outside. That's not to say it couldn't be the far end receiving your call but at least you could be definitive that it wasn't the inside wiring and have PacBell out to test the line which, at that point, shouldn't cost you anything.

 

[spikeychappie]

I can't actually see which cores of the incoming cable are connected - it's behind the tamperproof cover which I have not removed (yet!). But the technician told me he was just connecting two cores.
I already pluged my modem into the test jacks and got the same 24K connection speed - so the house wiring seems OK.
PacBell say the line tests out OK, and it is fine for voice communications. Just slow for internet, but still way above the minimum guaranteed bandwidth which is 9600 baud or something...

 

[vaoldschl]

Well, if they're only going to guarantee 9600 baud I'd say you won't have much luck in that arena. Being essentially a telephone guy I'd attribute it to the equipment doing the dialing and answering, if you know it's not your modem, see if your ISP has another number you can try or if anyone you know uses the same number with different results. As for the NID, I'm inclined to think the technician who installed it meant two pairs because generally for plain old telephone service(aka POTS) it takes a pair, one for tip and one for ring. As for the voltage you measured, ring voltage on a telephone line comes in around 90, you probably were receiving a call when you tested it. Sorry if this isn't much help, if you want to pursue telephone information check out

http://www.phone-talk.com,

they have some inside wiring and residential configuration info.