Re: 56K Modems

Josh Hillman ( (no email) )
Wed, 11 Feb 1998 13:00:07 -0500

I don't remember who said what here, but in order to acheive X2/K56Flex or
V.90 (the ITU-T recommendation as of 2/6/98), the ISP does NOT have to have
PRI or BRI lines. So long as the connection between the ISP and the telco
is 100% digital and each dial-up channel can handle the 56k or 64k, you can
do it. Our lines are "DID" lines (digital inbound dialins) carried
acrossed channelized T1s. DIDs aren't PRI or BRI and yet deliver the 56k
just fine. With our Max 40xx boxes (presently 5.0Ap42), the highest
user-download speed that I've seen is 48000.

Also, just because the ISP may have 56k access servers and is connected to
the telco via digital link, it doesn't mean the customer can connect at
anything higher than V.34. If there are any additional a/d conversions
between the end-user and the telco, it won't work. This is frequently
encountered when the user's phonelines are piped through a remote
concentrator (repeater) in their neighborhood. Also, the distance of the
analog segment of the connection will make a big difference. Typically,
the distance delimeter is around 18kfeet, but of course there are

For those of you who are interested in the ITU-T V.90 info, it's at:
Agreement Reached On 56k Modem Standard

Josh Hillman

> Rik Thomas wrote:
> > I would hope by now everyone would understand what it takes to get
> > a Flex or X2 connection...oh well. Makes for great competition...not.
> From: John Barrett <>
> With a qualifier, I beg to differ with you. I failed to mention (Rather
> importantly and reminded of it by Mitch.... You do need at least ISDN
> Bri. X2 requires a digital circuit to run over.) But the Courier I-Modem
> will host a connection using X2 Server mode or X2 Symetrical modes.I run
> an NT Server with a Courier I-modem V-Everything and serve up an X2
> connection at 44kb everytime I dial into my machine remotely with my
> Sportster X2. Now would I recommend this for production?? No.. no one in
> there right mind would but it works for me to remotely access my server
> for online maintenence.
> Not to start a pissing contest, just wanted to correct myself. Sorry for
> the misrepresentation.