Re: CU-newbie question...

Jay Shoup (
Mon, 15 Apr 1996 18:25:45 +5000

You might want to check to see how the DTR/DSR/CD settings compare to
the old modem. You might also want to compare the compression and
error checking settings comparing the old modem to the new. One
important aspect of this is flow control, most modems allow two types
of flow control, hardware and software, hardware is preferred as it is
much faster. Look in your modem books for XON/XOFF and be sure the
modems are set to hardware. Also check to make sure that the winsock
you are using is setup for the modem you actually have.

The problem you describe sounds like a "data turn around" problem. The
modem must switch back and forth from the transmit and receive modes,
there are two channels assigned in 28.8 modems, one channel is a high
speed channel and the other is a low speed channel. The receiver send
Acks & Nacks (packet acknowledge and non- acknowledge) on the low
speed side, while the bulk of the data is sent on the high speed side.
V32 (14.4) and V34 (28.8) handle the switching between modes somewhat

I recommend turning V42 Bis off is you have compression in your
winsock turned on. Only one form of compression should be used. Also
it should match the settings of your POP. I assume, because your old
modem seemed to perform well that its settings were correct for your
and your POP's system configuration.

Good luck.....

> Hi everyone. I've been playing around with CU for a few weeks now, and was
> having nominal success with xmit/rec at 14.4 (Mac 660AV w/Geoport) and
> QuickCam. In an effor to increase the quality (quantity?) of xmit/rec, I
> just got a 2.8 Global Village Teleport Platinum modem. Reception has
> improved, but now, no one is rec my vid very well. It seems to barely
> trickle in, if at all, whether on a ref or direct connection. Interesting
> to note that when i pause, the image eventually makes it intact. Using the
> 14.4 Geoport, I was at least able to xmit fairly well, altho my recep was
> poor. I'm connecting to my ISP via a SLIP connection, and all my other TCP
> apps are working fine, and reflect the increase in throughput. Any clues??
> Here's what I've got:
> Mac Centris 660AV/230/24
> System 7.5.3
> Open Transport 1.1
> CUSeeMe v0.83b3
> Connectix QuickCam
> QuickTime 2.1
> These seem to be the pertinent details...if there's anything else that I
> should mention, please let me know. I've pared down my system requirements
> via the Extensions Manager (thinking that it was an overhead problem), but
> that hasn't seemed to help any.
> I'd really like to get this working ASAP, and not have to go back to the 14.4.
> Post here, or to me directly at
> Thanks a ton!
> Kim_A_

FTP : anonymous login

Jay Shoup
Eigenmann Hall RM 1281
Indiana University
Bloomington, Indidiana 47406
(812)857-2240 <Voice/Fax>