Re: 56K Modems

Michael Whisenant ( )
Fri, 13 Feb 1998 12:19:41 -0600

>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
Yes, Trunk-side terminated T-1 lines will work. The key is to make sure
the CO does not send the T-1 first over a channel bank. The only switch
type that we have ran into problems with was a DCO. If you carrier uses
any flavor of ATT/Lucent, Siemens, Northern Telecomm, Stromberg it is
easily to configure without PRI/BRI.

>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.
To comment we have demostrated in real world conditions that users can
download at 6.3K using compression on an actual 54666 connection using x2.
The normal connection is 52000 to 53333 with over 95% of users using this
technology, that are not behind a C-SLIC wiring configuration, connecting
at or above 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
This is true. In our coverage area the teleco plant is built to either a
12K or 24K plant configuration. In the 24K plant configuration if the
subscriber is receiving their pairs on older 20-22AWG wiring it is great.
If they have newer 24 gage then we have seen a slight fall off in speeds.

>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.
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