On Wed, Aug 14, 2002 at 11:13:57AM -0600, [EMAIL PROTECTED] wrote: > I found a modem at a thrift store that appears to be in new > condition. It is a Courier I-Modem ISDN 128kbps v. everthing US > Robotics and it is external. [...] Do I need to have special > service to make this work or just change the phone wall connector to > fit the larger ISDN connector.
You don't want the modem. For much of the US phone system a voice call gets digitized at 64 Kbps and is hauled around that way. Once the call is bits the bits can be copied perfectly. That's why long distance calls these days usually sound as good as local calls. (That is also why analogue dialup modems were never going to match or beat 64 Kbps--they get turned into a 64 kbps stream anyway.) ISDN was based on the clever idea of bringing that digital connection out to the end user, and it was a way to do it over copper wires without nasty distance limitations. The reason for the "128" is that they put two of these 64 kbps channels on one circuit. One could be used for a voice call and the other a data call, or both voice, or both data--possibly bonded together for 128 kbps. But ISDN never really happened. First, because phone companies are not good at innovation and couldn't figure out how to market it. (Hell, much of the time you could call asking to buy ISDN and not be able to find anyone at the phone company who had heard of it.) Second, ISDN was "circuit switched" on the cusp of the "packet switched" era. That is, instead of, say, a DSL connection where you might fling a packet at any IP address on the internet, ISDN was a data phone call from one phone number to another phone number. These two problems combined to make ISDN very expensive. Ironically, one flavor of DSL (IDSL I think it is) is actually based upon ISDN techology for putting the bits on the wire. ISDN does still exist. It is used by radio stations for interviews across the country or across oceans, and even recording studios will sometimes use it to link up a remote musician. The reason is because it doesn't have the nasty delay of a satellite connection and it is more reliable than sending bits over the internet. > And second question, as a Linux novice, will I be able to make this > work if I buy it? It is only $25.00 so it seems like a good > deal. -Jeff Linux does have ISDN support, but you don't want ISDN just because you can buy a modem for cheap. -kb P.S. When a phone company says "64 kbps" they mean 64,000, not the 65,536 preferred by a computer person. -- redhat-list mailing list unsubscribe mailto:[EMAIL PROTECTED]?subject=unsubscribe https://listman.redhat.com/mailman/listinfo/redhat-list
