I think he means ground start phone trunks instead of loop start phone lines.
trunks are have better signaling for incoming/outgoing call generation.
You bring tip to ground for a second to get dial tone.
You should also check to make sure you are seeing the proper ring voltage
at the modems. Ring voltage has a huge spec but normally its 115v AC
30-45 hz.
> Hmmm, lessee, 16 RS232 cables between one PM and one MP/16 makes for
> 16 signal ground connections. The POP that does have the problem is
> my base POP where all the computers are, so there's lots of RF flying
> around, so ...
Do you use shielded cable? Is all the equipment grounded properly?
I shield which is grounded at both ends is a conductor. I conductor can
carry current, current inducts noise. Ground your shields at one end
only. Use nice big grounds which are properly installed (scrape paint
off the screws, solder if needed).
> The no-answer problem *was* much worse in the past when I used flat
> RJ45 cables. Switching to cat3 cables vastly improved things. Going
> from cat3 to cat5 made no detectable difference, nor did putting Amp
Is this for the phone lines coming in? I can't think how a better
RS-232 cable would help the modem detect ring. Are you sure the modems
are not answering, or are they answering but not connecting?
-Matt