CUSM, ISDN & Mac, questions

David S. Bennahum (
Wed, 15 Feb 1995 10:55:13 -0500


I use cusm with an ISDN connection from my home at 56k/sec. This speed is
the maximum limit my Mac IIcx port can handle, so even though my ISDN
hardware can handle transmission rates of 128K/sec, the Mac IIcx cannot.
However, there is a solution. I am getting a Planet ISDN board from Sagem
USA that fits in my NuBus slot and handles speeds of a solution
seems in sight. But here is the dreadful catch: MacPPP, MacSLIP do not
handle speeds over 56K/sec, there is no way to then, it seems, have a SLIP
or PPP connection *and* 128K/sec ISDN! You have to slow down to the
software's limitations, even though the hardware is primed to go at a
faster speed! Yuck.

Please tell me this is not true. Does anyone know of a "direct IP"
solution that supports 128K/sec for the Mac? It should be one that allows
me to run cusm and every other TCP/IP app (Eudora, Netscape, etc.), not
just proprietary software (as in corporate networking solutions) that come
with the "solution". There are commercial solutions based on proprietary
applications that are not compatible with cusm, etc. that handle 128K/sec,
but that would not work for me. So? I hear there is nothing out there in
terms of Mac software that allows 128K/sec direct IP *and* the running of
third-party IP applications like cusm, newswatcher, whatever. One other
catch -- no ethernet, appletalk, and so on should be required -- this is a
direct ISDN connection from a phone jack in my wall at home (AT&T 5eSS
custom, I think). Solutions made for LANs probably a)cost a fortune and
b)aren't meant for a single user at home.

Anyway, this is the current state of ISDN at home with a mac, it seems.

Any solutions, insights, brilliant hacks (like recoding MacPPP to handle
128K/sec) would be hugely appreciated.

Btw, this really does have to do with cusm. At 128K/sec I will finally be
able to send & receive at a decent frame rate.


David S. Bennahum
144 West 19 Street, Apt. 3C
New York, NY 10011
Voice: 212-929-4317
Fax : 212-645-1767
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