perl@PacBell.COM (Richard Perlman) (06/07/91)
In article <27@ryptyde.UUCP> dant@ryptyde.UUCP (Daniel Tracy) writes: >...There is a physical limit stating you cannot open two different > channels on the same line (unless you're using ISDN!). Not quite true. Using Data-Over-Voice (DOV) technology you can run up to 19.2 async or 64kbs sync on top of a voice line. Most phone companies (at least the RBOCS) offer (or offered) a central office based "LAN" using DOVs and (in most cases) AT&Ts DataKit VCS (Virtual Circuit Switch) although Pacific Bell uses a Gandalf product. Streching the point further, UNIX Layers and "uw" both offer the capability to multiplex multiple "logical sessions over a single line. And AT&T offers a number of terminals (going back to the BLIT) that have similar "smart" features (when connected to the right host) -- "What is politics, after all, but the compulsion to peside over property and make other people's decisions for them." Tom Robbins -- -- Richard Perlman |*| perl@pbseps.sf180.pacbell.com |*| (415) 545-0233
dant@ryptyde.UUCP (Daniel Tracy) (06/08/91)
Responding to the following: "Not quite true. Using Data-Over-Voice (DOV) technology you can run up to 19.2 async or 64kbs sync on top of a voice line. Most phone companies (at least the RBOCS) offer (or offered) a central office based "LAN" using DOVs and (in most cases) AT&Ts DataKit VCS (Virtual Circuit Switch) although Pacific Bell uses a Gandalf product. Streching the point further, UNIX Layers and "uw" both offer the capability to multiplex multiple "logical sessions over a single line. And AT&T offers a number of terminals (going back to the BLIT) that have similar "smart" features (when connected to the right host)" But this is still a single "channel". Similarly, with ISDN, you could communicate via modem and voice at the same time, but both must be at the same location. Again, only one "channel" is opened. Anyway, it may be possible and could be happening. I was just giving a generalization. Someone was excited about PacerTerm because it could carry on multiple sessions simultaneously, and it sounded like he thought he could call multiple BBS's with one line/modem.
6500wong@ucsbuxa.ucsb.edu (Ki Ching Wong) (06/12/91)
>But this is still a single "channel". Similarly, with ISDN, you could >communicate via modem and voice at the same time, but both must be at >the same location. Again, only one "channel" is opened. Anyway, it may >be possible and could be happening. I was just giving a generalization. >Someone was excited about PacerTerm because it could carry on multiple >sessions simultaneously, and it sounded like he thought he could call >multiple BBS's with one line/modem. I believe I started all this. But still back to the basic, I wasn't excited about PacerTerm's multiple session capability because I want to call up several BBS with one modem line. I was wondering if it can have multiple UNIX sessions over one modem connection, like MacLayers. I found MacLayer quite fascinating but lack of support for zmodem (and I can't seems to get xmodem to work in Layer either) is too bad. I was hoping that PacerTerm will do just what MacLayer can plus the zmodem support. Apparently, that's not the case. -Ki Wong 6500wong@ucsbuxa.
conrad@popvax.uucp (M20400@c.nobili) (06/12/91)
<12028@hub.ucsb.edu> 6500wong@ucsbuxa.ucsb.edu (Ki Ching Wong) writes: >I believe I started all this. But still back to the basic, I wasn't >excited about PacerTerm's multiple session capability because I want >to call up several BBS with one modem line. I was wondering if it >can have multiple UNIX sessions over one modem connection, like >MacLayers. I found MacLayer quite fascinating but lack of support >for zmodem (and I can't seems to get xmodem to work in Layer either) >is too bad. I was hoping that PacerTerm will do just what MacLayer >can plus the zmodem support. Apparently, that's not the case. >-Ki Wong >6500wong@ucsbuxa. Hmmmmm. Yet another situation where Liaison provides a very nice answer. I just posted an explanation of this whole thing a couple of days ago, but I did not address this thread specifically enough. Dialing in to a Liaison router I can establish _many_ terminal sessions at once to all sorts of places using NCSA Telnet 2.4b11 (MacTCP) for example. And I can simultaneously be using several other TCP/IP-based program, _and_ several AppleTalk based services (printing, filesharing, etc.).... I of course do all of my file transfers using ftp across this connection. (Well, actually I often use WMAC and RMAC when logged into CMS on our IBM mainframe....) Liaison provides all of the capabilities that people in this thread wanted, and provides them well. Additionally, it provides _much more_ than what people in this thread were even thinking about.... Check it out.... +---- C o n r a d C . N o b i l i ----+ | | | Harvard University | Internet: conrad@harvarda.harvard.edu | | Office for Info. Tech. | conrad@popvax.harvard.edu | | Information Services | BITNET: CONRAD AT HARVARDA | | Technical & User Services | CONRAD AT HARVSPHB | | 1730 Cambridge Street | voice: (617) 495-8554 | +---- Cambridge, MA 02138 | fax: (617) 495-0715 ----+