US Robotics 005605 modem and VOIP

I think the Collin is trying to get his modem working over a VOIP connection, not a VOIP connection working over his dialup internet access.

Having said that, Voip over dialup can work, if you're using codecs that provide proper compression, but a 56K modem connection over VOIP is probably not going to work very well.

Collin, to do some basic trouble shooting on this problem, make sure you get dialtone with a POTS phone plugged into your Sipura ATA(it's not a modem) if you don't, there is trouble with your ATA.

If you do get dialtone, plug your USR modem into a regular POTS line.

If you don't get dialtone, your modem/drivers are screwed up.

If you do get dialtone, you have a physical connection problem between your modem and the ATA(cords, jacks etc.).

Randy

Thanks for the responses.

First of all, I don't have a problem getting a dial tone with my HP All- in One printer/scanner/fax unit, only the US Robotics External 005605 seems to have a problem with a dial tone. Perhaps it's a driver problem, since the OS does recognize that the modem is connected to a serial port when I have it connected with the serial cable, and in USB mode when it's connected to the USB port.

There's also the possibility that something must be re-configured within the Sipura 2000 setup - or the US Robotics modem may simply be broken, since the HP all-in-one received the dial tone upon initial power-on testing.

Faxing shouldn't be a problem if I reduce the baud rate with my software. The HP doesn't allow for that, though and that's why I'm trying to get the US Robotics external configured.

Perhaps it's time to just shell out $7 for one of these internal's:

"Jeremy" wrote in news:Jksqe.723$fa3.689@trndny01:

1. The Sipura 2000 is NOT a modem, its ATA (analog telephone adapter) which needs to be plugged into ethernet port of a router.

1. You wont be able to get VoIp working on a dial up 56k connection, it's not fast enough on the upload leg. I believe it's possible to set your modem for equal speed both ways in which case you may be able to use softphone (e.g. Xten Lite). Regards, Martin

You won't get VoIP working with a dialup modem, there isn't enough bandwidth. VoIP requires a broadband connection.

Before you say Skype works with dialup yes it does but it uses a proprietary protocol and quality on dialup is crap.

BTW the Sipura 2000 is an ATA not a modem.

Ivor

I have had much better results by configuring my modem as a Class 2, rather than the default Class 1, when faxing on VoIP.

The Class 2 protocol does not spend nearly as much time "training" during each fax. It also hangs up faster after the fax has been transmitted. It also does not utilize error correction, and that saves time.

Class 1 also has the nasty habit of slowing down as multiple pages are transmitted. It might start out at 14,400 for the first page, then drop to

9600 on the second page, 7200 on the third page, and 4800 on all the subsequent pages. I have experienced much less of that when transmitting in Class 2 mode.

Not all modems support Class 2, but if yours does, by all means try it. You may find that it significantly reduces transmission time.

*WRONG*. The Macintosh software "PGPphone" was doing this years ago. Human speech really doesn't need to bandwidth many people it requires. Several stupidities of most modern fancy-digital-phone-systems conspire to heavily degrade the signal, such as the use of automatic gain controls, trying too hard to keep the signal from clipping, trying to spend all your cycles processing and analyzing and digitally throbbing the prostate of the signal in order to try to get it to be more comprehensible by whatever cockeyed scheme your particular intern thought of, etc., etc.

If you throw out almost all the digital analysis and present just a few bits of signal, *at the zero crossings* instead of smoothed and merged and FFT'ed into powerbands and with all the speech timing thrown out, you actually get a quite intelligible signal.