> Given the amount of bitching about this modem and that modem not
> working with the PM3, I thought I'd post the results of an experiment
> done for me yesterday by a user here. They are with the old modems,
> but the show the point nonethless.
>
>
> What IS different? The call path. PRI #1 originates in the CO local
> to the POP and the user, PRI #2 is hauled in from a remote CO.
>
> For PRI #1 and this user the call path is
>
> user <--phone line--> CO-1 <--PRI #1--> PM3
>
> For PRI #2 it's
>
> user <--phone line--> CO-1 <--voice trunk--> CO-2 <--PRI #2--> PM3
>
> The problem is that voice trunk. Just because you have a PRI or CT1
> with 8-bit-clean trunk-side attachment doesn't mean the trunks used to
> deliver calls to your PRI/CT1 are 8-bit-clean trunks. Quite often
> they are not. For this path, in fact, I happen to know that they
> virtually never are.
>
> I know good trunks exist for the path, because I can call either PRI
> from the other and establish a 64k ISDN connection. Those good trunks
> just aren't used for voice calls, which are presumed not to need them.
> (Actually, I have evidence a lot of voice calls along the path in the
> other direction, CO-2 to CO-1, do use 8-bit-clean trunks.)
This would also explain why a person can call in one time, and get a
terrible connection, or worse yet not even a connection. But, then turn
around dial back in and have a good connection. I have heard various
mumbling about switching at the CO, would this probably be in the same
boat?
Thanks for posting. It was very informative. It helps a lot in
understanding some of the jargon I hear.
Later
Kelley