BRI ISDN is 2x64K B channels + 1x16K D channel.
T1 PRI ISDN is 23x64K B channels + 1x64K D channel.
E1 PRI ISDN is 30x64K B channels + 1x128K D channel.
(Well, almost. 2 64K channels are used for the D channel as well as
additional signalling for the line, but that's close enough.)
>I reset my modem to use 56K bandwidth, and v.120, and was able to connect.
V.120 is an async protocol to run over a sync ISDN line. That isn't the
same thing as pure DOSBS. You are losing a lot of bandwith in using V.120.
>Isn't that really just using a throttled down B channel? What I mean is,
>Bell is charging me 2cents a minute for a channel which I could be running
>at 64K for the same price.
If the other end is using channelized T1 into their server - which I believe
you said they are - you simply cannot connect at 64K with them. Period.
Channelized T1 cannot accept 64K ISDN DATA calls - or 56K ISDN DATA calls
for that matter (AFAIK). It can accept 56K DOSBS data calls, and you can
run V.120 over it - but that's not needed and I advise against it.
The difference is in some areas there is a per minute charge on data calls
but no charge, or a lesser charge, on voice calls. This is how it is in
NYNEX land. So NYNEX BRI users can save a lot of money using DOSBS on their
BRI lines.
Also, for the server end, the only way to support 64K and 56K ISDN DATA calls
is to have a PRI line. Well, in some areas PRI is just not available, and
in others it is insanely expensive. So getting a channelized T1 line may
be the only, oronly pratical, solution - and it does allow at least for
56K DOSBS ISDN connections.
-MZ
-- Livingston Enterprises - Chair, Department of Interstitial Affairs Phone: 800-458-9966 510-737-2100 FAX: 510-737-2110 megazone@livingston.com For support requests: support@livingston.com <http://www.livingston.com/> Snail mail: 4464 Willow Road, Pleasanton, CA 94588