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From: (Fred Goldstein)
Newsgroups: comp.dcom.isdn
Subject: Re: ISDN - Numerous Newbie Questions
Date: Sat, 26 Dec 1998 03:24:02 GMT

On Thu, 24 Dec 1998 13:03:14 -0500, "Dave Rhodes"
<> wrote:

>1) DOV (Data Over Voice) - in converting my old analog phone line over to
>ISDN, isn't the phone company (Bell Atlantic) going to be a little bit
>suspicious when they see I go from about 600 minutes per day for data calls
>on the analog line to like zero minutes on ISDN (only going to use ISDN for
>the data over voice)?  Can I get busted as in huge fines or is this not
>illegal or ?  And I'm sure there's a way for them to find out on their end
>too, right?

Perfectly legal.  Like buying a cheap burger at Mickey D's without the
high-profit Coke.  My ISP advertises DOV on their web site
(, and even  loans out routers to DOV users.  Sure
Bell Titanic gets pissed, but that's what they're there for.  They cry
all the way to the bank.

>2) DOV - Connection Speed...I keep seeing people say that you can achieve
>speeds of up to 112K (56K X2) with ISDN and DOV.  Wouldn't it only be 106K,
>though, because of the FCC regulations?

No. DOV has no analog lines in it.  The "53k" limit in V.90 is only
there because of the impact of an analog line's DAC.  In fact, some
"56k" modems (X2 has this feature) can switch to 56000 bps
bidirectional mode (not pure V.110/56k, which is DOV, but still a full
rate) when they recognize both ends on a digital line. The whole "56k"
thing is a take-off on DOV.

>3) ISDN Adapter - I think I am going to go with the Sportster 128K internal
>ISDN adapter.  I was going to get the Courier I-Modem with V-Everything, but
>I read a couple of reviews of ISDN adapters and found that the Sportster is
>a) much cheaper and b) provides better throughput.  Any comments here?

Yeah.  Crock'o'hooey.  The Sportster Internal is an ISDN "Winmodem" --
it depends on Windoze DLLs to operate.  Throughput is okay, but you
lose flexibility.  Externals and I think the Courier are like generic
full  modems, with a serial-port interface, and work under any OS.
You just need to have a fast enough serial port speed (230 kbps
minimum if you use both B channels; 460 is better).    Also, verify
that there is good DOV support on the Sportster; it wasn't there
originally, though I think it has been added.

>adapter would you get if all you cared about was getting the DOV feature and
>then sheer connection speed/throughput?  I don't need it for faxes and I am
>not going to get any incoming calls if that helps...

I prefer Ethernet attachment, like the Netgear RT328/ZyXel Prestige.
Also Ascend and Cisco, though they get higher prices.

>4) ISDN ISP - I have narrowed it down to two local ISPs: one is about $7 per
>month cheaper, but also seems to have better hardware.  I pinged both of
>their websites and got about 260-270 on the more expensive one and around
>300-310 on the less expensive one.  Are there any other tests I could
>conduct to narrow it down?  I also divided the amount of subscribers each
>had by how many T1s it also had and of course the one that had the slower
>website had the better ratio.  So, I guess I am confused here.

You need to test throughput at several times of the day to various
destinations -- benchmarking ISPs is not trivial!  Also check for busy
signals during the 9-11 PM busy hour.

>5) I am not sure I really understand the whole idea of compression with
>ISDN.  Can someone please explain this to me?  Is it true that you could
>effectively double your throughput by going with an ISP that will enable
>compression for you on their end? I read that somewhere.  I just want to
>know a little bit more about this so that I can ask all of the ISPs if they
>can give it to me or not...

Compression works on ISDN just as on modems.  But it doesn't always
buy you much.  Web page text is compressible; GIFs are already
compressed and don't shrink more.  FTP of ZIPs won't get faster,
though unzipped files will usually get faster.  Compression doesn't
help latency (gaming).  And ISDN compression implementations are not
always uniform or interoperable; there are not good standards, and it
can be really annoying when things claim to have the same Stac options
but they don't work together.  I end up turning it off a lot for that

>6) Lastly, when Bell Atlantic converts my analog line to ISDN next week, is
>there anything I should look out for?  I am not just talking about leaning
>over the guy's shoulder, but is there anything I should look out for where
>they may try to "trap" me into confessing I'll be using DOV?  I know I am
>sounding paranoid... :-)

Hell, brag about DOV!   I'm pretty open about it.  (Just don't brag in
Virginia; do it quietly and call it a "V.110 56k modem".)  But you
should expect them to screw up the installation, mark your line as
"measured" for all calls, miss the date, etc.  They are as
enthusiastic about ISDN as they are about, oh, Castor Oil. They
provide it because a) Centrex needs it, which is all they care about,
and b) the regulators force them to offer it to non-Centrex
subscribers.  That's why they had nominal advertising which sucked so
badly -- it's how you meet an obligation, not get business.

Fred R. Goldstein   k1io   fgoldstein"at"
Opinions are mine alone; sharing requires permission.

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