IMHO ...If you want to transfer files I would use a simple command line FTP program. For communications I would check out an (asci) terminal emulator program like PCterm. or text pager software.
Henry 2011/12/12 Ken Brown <[email protected]> > You are not going to get anywhere near 56k using only analog lines. 56k > modems relied on one side (usually the ISP) having access to digital lines. > This allowed the modem to sync with the phone system clock and the A/D > conversion at the far end. Without this syncronization I believe the best > that could be done was 28.8k. But that was with dedicated hardware. > > > Is there a reason that you can't just plug in a couple of modems to the > same lines? > > If you are making a call then sending a short burst of data, then hanging > up, a slower modem (2400) or less might be faster. The high speed modems > took considerable amount of time negotiating speed when connecting while > your slow modem could connect send a bit of data and hangup in the same > period. > > Another low speed solution might be DTMF asterisk and the ATAs know how to > handle that and it sends 4 bits at a time. > > > ----- Original Message ----- > From: Bruce N [mailto:[email protected]] > Sent: Saturday, December 10, 2011 05:13 PM > To: [email protected] <[email protected]> > Subject: [on-asterisk] What Modulation/Demodulation add-ons for various > frequencies exist for Asterisk? > > Hi everyone, > > I have a situation where there is a PSTN line but there is no 56k Modem; > However there is a Linksys ATA with an FXO port attached to PSTN line and > registered to Asterisk. I want to stream "data" back and forth. No audio. > > I understand that is what a 56k modem best does in case of a PSTN analogue > line. I want to know if there is any method, algorithm (like using various > pitch sounds to send data) that I can take advantage of with or WITHOUT > using Asterisk? Currently, I am looking to send alpha-numeric in > 30-50 characters but later on, it can get larger so error correction, error > detection (maybe using a hash digest), and as fast data-transfer as > possible (close to 56k) is ideal. I am assuming that 56k modems are the > fastest possible over analogue lines (since they have patented algorithms > and chips specifically built for this purpose)?! > > Currently in Asterisk 1.8x there is a morsecode() application which is > really cool but of course it's very slow. Also, there is no Morse code > reader for Asterisk (I could be wrong; please correct me if so). Or a very > basic thing I can do is to use DTMF and assign each letter a number and > transmit/decode on the Asterisk side but it will be really slow for my > purpose. So, something like that should do the job but since this is to be > machine automated I am sure it can be much faster using various pitch > sounds in much smaller intervals per code. Another example of this is some > programs that exist for amateur radio operators where a radio along with > GPS can be used to track location of a car. > > Any input, however technically in-depth, is much appreciated. > -- * Henry Coleman* [image: Picture]
