Re: CU-SeeMe with direct modem connections

Geoff Rehn (EST)
Tue, 22 Nov 1994 08:05:37 -0500


At 11:05 PM 11/21/94 -0500, Michael Sattler, San Francisco wrote:
>At 13:49 11/21/94, Geoff Burian wrote:
>
>>I was basically wondering what kind of performance people
>>have gotten with a straight modem to modem connection (using SLIP
>>at 14.4 or 28.8Kbps).

Some months ago, I got both Macs and PCs to talk to each other over a
direct SLIP connection: InterSLIP on the Mac, Trumpet on the PC. Can't
recall the fine details (I did post to this list at the time) but I think
it might have been in the order of 2-3fps, at 14.4kbps.

>TCP/IP over a 14.4 kcps+compression modem gets you passable video (try it
>with NASA Select) but audio takes over 32 kcps (I believe) and so audio
>won't cut it (try it with NASA Select).

I haven't had much chance to fully try the (newer) Maven audio with the
delta-mod encoding, at 16kbps. So far, I haven't managed to get it to work.

It would seem to me that, if the video were paused, and Maven at 16kbps
used, an audio link might well be possible at a 28.8kbps modem link.

I am still wondering what gives best results (for video) over a modem: data
compression or not?

Geoff R.

---
Geoff Rehn
Academic Services Unit
Murdoch University    Western Australia
rehn@cleo.murdoch.edu.au