Re: SLIP and Cu-SeeMe cont'd

Christopher M Sedore (cmsedore@interrel4.case.syr.edu)
Wed, 3 Aug 1994 09:30:58 -0400


On Tue, 2 Aug 1994, Geoff Rehn wrote:

> At 5:26 PM 8/2/94 -0400, Jim B. Krone wrote:

> I am still undecided as to whether or not to use:
> 1. Compressed SLIP (ie. CSLIP) (ie. header compression)
> 2. Compressed data ie. MNP-5 or V42bis data compression.
>
> I don't think using data compression would help at all, as I imagine (in my
> naive understanding) that the video data is of course already compressed,
> and my understanding of modem comms is that using data compression can
> actually slow down the transer rates of already compressed data.

This depends entirely on your modem and compression method. MNP5 was
famous for slowing down tranfers of compressed data, but v.42bis is not
supposed to suffer from this.

> But on CSLIP for header compression, I don't know.
> I guess not. Does CU-SeeMe video data have headers, Cornell?

CSLIP works on IP headers which CU-SeeMe does use for communications.
I'd recommend using it.

In summary, I think best performance will be achieved with both types of
compression (not MNP5, but v.42bis) turned on, if you have a decent
modem. My Hayes Optima 28.8s yield the best performance in this case.
In any case, your performance should not be negatively affected by these.

-Chris

Chris Sedore
Maxwell School
Syracuse University