Re: ISDN question and sound bandwidth

damian goldstein (
Wed, 16 Aug 1995 22:22:29 -0400

>From: (damian goldstein)
>Subject: Re: ISDN question and sound bandwidth
>>Hi all,
>>This question does not strictly belong in the mailing list, but it is
>>cuseeme related.
>>We are an ISP in Dunedin, New Zealand. We are involved in a trial with a
>>handfull of schools, who are using cuseeme for Remote Teaching and general
>>video conference.
>>The schools are currently using 28.8 kbps modems.
>>The problem is this: If you transmit video at 10 kbps (the minimum) and you
>>want to talk at the same time (16 kbps) there is in reality not enough
>>The sound simply breaks up to much. The only way the users can talk to each
>>other is by locking the video transmission while they talk.
>>At this time, the only solution is to use ISDN. ISDN is only now slowly
>>starting to take off in New Zealand. I have ordered a ISDN card for our
>>Linux based dial-in server. That part is pretty clear for us.
>>However, I have no idea what kind of ISDN equipment is to be used at the
>>The schools are using a mixture of Macintosh and PC computers.
>>- What kind of ISDN equipment should be used?
>>- What software drivers must be used to connect to s CSLIP dial-in system?
>> The InterSlip (or Trumpet Winsock) software should be able to 'talk' to
>> the ISDN equipment, like it was a modem.
>>I have noticed that many cuseeme users on this list are using ISDN.
>>I would greatly appreciate *any* information on how this is done, including
>>software setup, brand-names of ISDN equipment and phone- or Fax numbers of
>>companies which sell this equipment in the U.S. or in Europe.
>>We understand that the New Zealand ISDN system is compatible with the 'EURO'
>>On a related note: Is it true or not true that development is going on, on a
>>cuseeme sound system which uses much less bandwidth? I recall reading
>>something about a new system which uses only 5 or 8 kbps.
>>Any information whatsoever is very welcome.
>>Bart Kindt
>Hey bart,
>That sure was alot of questions, but I hope I can in fact shed some light
on your queries.
>I work for a telecommunications company in New York City, and am in the
midst of starting our own ISP (yes, yet another one). We will be offering
ISDN to our customers and for a long time have dealt with the headaches of
ISDN. However, we have succeeded and so will you.
>There are a host of products that can accomplish different application and
here are some descriptions:
> ADTRAN( has the ADTRAN 2x64, which can utilize the
seperate B channels for video codex apps., or for multiple site
connectivity. They also have the ADTRAN 128, and the 128 Express, which can
establish a 2B connection using the BONDING protocol. The Express also has
an RJ11 for a single line phone/fax/modem. Also, there is the ADTRAN 512,
which can, yeah you guessed it, give you a 512Kbps pipe.
> Motorolla( has a few products also. The TA210
($400-500), has an RJ11 jack, and an RS232 connection which we use in the
office now for our ISDN internet connection. I believe it may be limited to
64Kbps, but don't qoute me. It is a good price. For the other products
visit their site.
>If you are looking for an internal PC/MAC board solution, a french company
named Euronis makes a Mac specific board called the Planet board. They also
make a PC version. Digiboard makes the PCIMAC card which can accommodate
1,2,3, and 4 BRI ISDN lines. The rest escape me at the moment, however if
you'd like to call or e-mail me with more specific questions, I would be
glad to give you some help because I know I will be shortly asking for some
in return seeing as I have just started my CU-Seeme experience. (I don't
even have a video board: long story). The same goes to anyone else.
>Damian Goldstein
>(212) 627-4200, extension 255