Speed on an ISDN link....

David Watson (dwatson@metz.une.edu.au)
Sun, 9 Jul 1995 17:27:37 +1000

I've noticed over the last few days a discussion on frame rates over
ISDN... etc. When connecting to an ISDN line (say PacBell) do you have a
particular card that goes into your machine or is it a "direct" connection
to your serial (modem) port via an external adapter?

We are still out in the woods for ISDN down here so have to use modems. On
a Mac the serial port speed is only 57600 bp/s so unless a faster port card
is put in... you have a built in govenor. If you share the serial ports (eg
have the modem and the printer "running") your port speed drops to about
19,000 b/ps. We have gotten around the degradation by using dual port
serial cards that support/allow output to 230,000 bp/s per port. Would be
interested to hear from the ISDN connected folks as I wonder if a "trick"
is needed to get the best out of an ISDN connection.

David Watson School of Health
Lecturer University of New England
Email: dwatson@metz.une.edu.au Armidale, NSW Australia 2351 GMT +10 Welcome Mat out...
>>>>>>>>Phone: 61-67-73-3668 Fax: 61-67-73-3666<<<<<<<<<<<<
URL: http://www.une.edu.au/~dwatson