Re: ISDN instead of 28.8 baud for video conference question

Ulrich Kliegis (
Thu, 6 Feb 1997 18:46:18 +0100

> At 10:42 PM 2/5/97 -0500, you wrote:
> >I want to use a single channel 64kbs ISDN connection (it's half the
> >price of 2 channels and it's much faster than 28.8 baud), for
> >videoconferencing on the internet with my PC.
> >
> >Please advise if you have a suggestion as to where I may find
> >information on how to set up this connection and successes
> >experienced by others.
> >
> >Thanks in advance for any suggestions you may offer.
> >
> >
> As far as setting up the ISDN connection itself, talk to your
> internet service provider (ISP). They should have all the info you
> would need. There is nothing special you need to do with CU-SeeMe to
> get it to work with ISDN, except to adjust the MAX transmit and
> receive settings to take advantage of the increased bandwidth.
> Bill Woodland (Squeek)

Speaking from the position of someone who uses CU regularly with
ISDN, I can confirm that if your ISP does not restrict the data rate
for UDPs you can really get the 64 kbps in both directions. But you
should be aware that many reflectors demand a ceiling value of 20 or
even 15 kbps, and you are thrown out immediately if your settings in
CU are higher (nb, the settings, not the actual rate!)

Moreover, the receiving end may have a problem in getting your video
in an unscrambled way. You always get the optimal image quality if
you match send and rec rates of both sides.

The big advantage, however, of having CU running on an ISDN line is
that you can simultaneously download news, send and receive mail,
chat on irc and surf the web without seriously degrading th image
quality. I reserved 15 kbps send and receive rate for CU (I dont use
sound) and am happy with that.

Definitely recommended.

Don't flame me, I'm only the keyboard player...

Ulrich G. Kliegis Phone: +49 431 331144 Fax: +49 431 331146