I don't think that the solution is practical. I was more concerned with whether it was in fact possible. Of course, the NAT and PPP method is superior but I was curious as if a modem could actually be split as asked. It was more of an academic excercise and challenge then anything else.
On Fri, 20 Sep 2002, Harry Stangel wrote: > Why do you need 2 channels? Why not use one host as a 'master', > running NAT and PPP out its modem, and the other host as a 'slave' > connected to the 'master' host through their ethernet ports? > > Harry > > ----- Original Message ----- > From: "Chris McKenzie" <[EMAIL PROTECTED]> > To: <[EMAIL PROTECTED]> > Sent: Friday, September 20, 2002 2:32 PM > Subject: [vox-tech] Modem question . . . I think it is possible > > > > I know the post is a few days old but I was intrigued with the idea. > > modems capable of the v.34 standard have something called an auxiliary > > channel by which it can exchange information on such things as line > > quality. It can code using nonlinear, precoding, and 16-trellis along > > with most modern being able to do 32 and 64 state trellis depending of > > course on what type of bit (dibit etc) you want to transmit at. Here is > > the trick: Because of the ability to use such things as assymetrical > > transmission and the use of trellis coding, and echo cancellation, each > > modem will have an idea of sender and reciever. For the first modem, the > > other modem will be a sender and the other end of the ppp will be a > > sender. This essentially sets what could be a master slave model in order > > to do correct splitting, with hopefully little interference (via the > > trellis encoding). Here is how it would work: > > > > Computer 1 is master > > Computer 2 is slave > > > > ppp ISP is ISP > > > > Initiate the connection with the master to ISP and send a request for > > 16-state trellis encoding at 14400 bps. Ask for 16-state send and > > 16-state receive. Put the master on 32-state trellis recieve > > without confirmation via the auxiliary making each other > > baud recieved as null or noise. > > > > Place slave in 16-state trellis before connecting. Because of the > > trellis, it will interpret the data being sent as noise and adjust phase > > correctly to the nulls. > > > > When it sends out a request, the ISP with 16 state trellis which is synced > > with the master will interpret it as noise and ignore it. However, the > > master will take the signals in as extra data. As long as the master can > > split every other bit and maintain parity and whatever, it has now set up > > two channels, one 16 bit with the other laptop and one 16 bit with the > > ISP. Each other end will take the 'excess' data as noise and ignore it > > because it is not in sync. You now have two linked connections over one > > line. > > > > Truly, the slave still goes to the master which in turns goes to the ISP, > > however, this would be a sane operation of 14400 bps and a technical modem > > split. Implementing it however, is another thing . . . shouldn't be that > > difficult but also shouldn't be that worthwhile. Anyway, that is all for > > now. > > > > > > Sincerely, > > Christopher J. McKenzie > > > > [EMAIL PROTECTED] > > [EMAIL PROTECTED] > > H: +1 818.9917724 > > C: +1 818.4293772 > > 1815 Mesa Ridge Ave > > Westlake Village, CA 91362 > > > > _______________________________________________ > > vox-tech mailing list > > [EMAIL PROTECTED] > > http://lists.lugod.org/mailman/listinfo/vox-tech > > _______________________________________________ > vox-tech mailing list > [EMAIL PROTECTED] > http://lists.lugod.org/mailman/listinfo/vox-tech > Sincerely, Christopher J. McKenzie [EMAIL PROTECTED] [EMAIL PROTECTED] H: +1 818.9917724 C: +1 818.4293772 1815 Mesa Ridge Ave Westlake Village, CA 91362 _______________________________________________ vox-tech mailing list [EMAIL PROTECTED] http://lists.lugod.org/mailman/listinfo/vox-tech
