Re: Can't Get Carrier from PM3 to Bell Canada

Mike A Lyons (lyonsm@netbistro.com)
Thu, 19 Dec 1996 19:43:18 -0800 (PST)

On Thu, 19 Dec 1996, Evan Champion wrote:

> Status: DOWN Framing: ESF Encoding: B8ZS PCM: u-law
>
> Receive Level: +2dB to -7.5dB

> Hum, as I recell when the line is disconnected, the Receive level reports
> a fixed number like -22.5dB rather than a range, so that must mean that
> some sort of life is going on there.

Ours was pretty much the same thing: a receive level of -22.5dB until the
telco finally turned the things on at which poing it went up to +2dB to
-7.5dB. Only obvious difference I can see is that ours say "Status: UP".
;-)

> Could you do me a _REALLY_ big favour and check your wiring to see what
> it is? Was it the standard Livingston wiring? And does your wiring use
> all 10 pins of the RJ-45? Our wires only use 8, and one thing we thought
> was that perhaps when they wired up the breakout for the PairGain they
> started it at off 1 wire off... That would be enough to get the PairGain
> to report the link is electrically OK because you'd still get 1 of the 2
> receive/transmit wires hooked up.

That's probably something like what's going on. We just used the cables
that came in the box with the PM3's and it worked for us. These are the
two-pair cables with RJ45's on the end, laid out on the connector as one
pair, then a one-pin gap, then the next pair (so pins 1+2 are RX and 4+5
are TX?). The Livingston manual isn't clear about whether the pairs in the
cable are supposed to be crossed over or not (or which way they are
crossed, if they are) and I'm not partial to the idea of taking 23 of our
lines down just to check. Our HRU's are locked in a cabinet owned by the
telco so I have no way of checking how the female RJ45's are wired. :-(

-mike