🚀 go-pugleaf

Hello all,

Just wanted to relate my experiences with the new breed of DSVD modems
(specifically the USR Sportster Vi DSVD 28.8 modem), and ask a few questions.

First of all, these things actually work. I guess I've been around computers 
so long that it's amazing when a product actually lives up to the hype. Here's 
the scoop for those of you that are interested.

First, you must append -SSE=1 to your AT command; this enables DSVD mode. It's 
off by default. Otherwise the modem acts like a "normal" V.34 modem in every 
way.

When a data/voice connection is initiated, the handset is muted. Then, after a 
brief pause while the modems connect, there is a short scratchy noise, a 
series of beeps, and then BAM! you're connected via the modem and you can 
talk, too. The full duplex voice channel is fairly clear. That's not to 
say that it's crystal clear, but there is little or no loss in voice 
quality, just a little scratchiness around the edges. Sometimes I got a 
strange "echo" effect on my end, but the voices were still relatively clear.

According to USR, 9.6kbps goes to the voice channel and 19.2kbps goes to the 
data channel. However, we were getting around 2300 cps for data transfer while 
talking, so the voice channel can't be taking up very much or else it's being 
compressed.

At any time during the connection, you can hang up the phones, which closes 
the voice channel and the data channel gets full 28.8kbps. This does indeed 
work; once we hung up, our transfer rate went up to about 2650cps.

During a data connection, if you pick up the phone, the modem "rings" on the 
other end. The phone itself does not ring; just the modem. And you hear a 
ringing tone on the handset. Once the person on the other end picks up the 
handset, there is a short scratchy sound and then you're talking to the other 
person again. The transfer rate goes back down to 2300cps or so.

Furthermore, we played an extensive (2+ hour) game of Duke Nukem 3D over the 
modem while talking to each other, and had no problems at all. I'm very 
impressed with this product!

One of the nicest things about it is that you can effortlessly switch between 
voice, voice/data, and data. It struck me while transferring files and doing 
other collaborative things with the person on the other end that this was just 
a far more natural way to work with modems. You can really walk someone 
through sending you a file, or tech support, or just get more work done rather 
than resorting to a second line for the same effect-- assuming that the people
on both end have a DSVD enabled modem. Suffice it to say that I 
am very satisfied with the product!

Now, for the questions.

1. Will DSVD modems from different manufacturers work together? The documents 
I could find related to this on the WWW seem to indicate "yes," that any modem 
branded DSVD follows the DSVD spec and will interoperate. Anyone know for 
sure?

2. What's this I head about ASVD and the other technologies that are to 
"supersede" DSVD? Fortunately, this USR model is the only Sportster that has 
flash ROM, so I assume that USR will keep me current.

Any comments or questions welcomed! And of course I do not in any way represent
or work for USR.

Jeff Atwood
JAt...@a.crl.com