d001ucsac@bsu-ucs.uucp (Stephen P Kendall) (03/27/91)
I'm connected to a university VAXcluster through a DECserver 500 (which
says it uses LAT V5.1) through an AT&T ISN network. The ISN network is not
a LAN in the usual sense; it connects to the terminal or PC through the
COM port (19.2 kBaud) rather than through special network hardware.
The HELP menus on the DECserver mention an option to SET MULTISESSIONS ENABLE,
which then allows "multiple terminal sessions, each capable of a single LAT
service session" through the "TD/SMP protocol". This seems to imply that
with a "session management terminal" or a PC running suitable software, that
multiple simultaneous connections to the DECserver's services are possible.
I have found no further reference to this capability, either in the grey wall
or the online docs.
My question:
1) Is it possible to do this on a PC, given the hardware setup above
(not on a true LAN-style network, but connected to the DECserver
through a COM line)?
2) If so, with what software?
Thanks in advance, even if (as I suspect) this is not possible.
--
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{}Steve Kendall {}D001UCSAC@BSUVAX1.BITNET {}ALSO: {}BSD UNIX 4.3: {}
{}Ball State U. {}d001ucsac@bsu-ucs.bsu.edu {} 00spkendall@ {}kendall@ {}
{}CS Undergrad {}d001ucsac@bsu-ucs.UUCP {} bsu-ucs.bsu.edu{}bsu-cs.bsu.edu{}
{}{}{}{}{}{}{}{}{}{}{}{}{}{}{}{}{}{}{}{}{}{}{}{}{}{}{}{}{}{}{}{}{}{}{}{}{}{}{}{}cmilono@netcom.COM (Carlo Milono) (03/28/91)
In article <1991Mar27.001042.283@bsu-ucs.uucp> d001ucsac@bsu-ucs.uucp (Stephen P Kendall) writes: > >I'm connected to a university VAXcluster through a DECserver 500 (which >says it uses LAT V5.1) through an AT&T ISN network. The ISN network is not >a LAN in the usual sense; it connects to the terminal or PC through the >COM port (19.2 kBaud) rather than through special network hardware. > >The HELP menus on the DECserver mention an option to SET MULTISESSIONS ENABLE, >which then allows "multiple terminal sessions, each capable of a single LAT >service session" through the "TD/SMP protocol". This seems to imply that >with a "session management terminal" or a PC running suitable software, that >multiple simultaneous connections to the DECserver's services are possible. > >My question: > > 1) Is it possible to do this on a PC, given the hardware setup above > (not on a true LAN-style network, but connected to the DECserver > through a COM line)? The ISN can provide multiple sessions as well, but to different ports on perhaps different hosts/terminal-servers. But you can think of the ISN as a very fancy and very long RS232 cable. To that extent, a PC or terminal can, in essence, be 'hardwired' to the LAT Terminal Server...and it is actually *there* where you get multiple sessions. I am not familiar with the DECserver 500, per se, but if you set MULTISESSIONS, then you have some form of key-stroke "hook" into the OS of the Terminal Server. Here is an example: You power on your PC, which is connected to an Async Port of the ISN...you fire up your favorite terminal emulator (with VT220, natch?)...you are then given an ISN prompt like 'DIAL:', and you enter some address (like 'cluster'), and you now have a virtual circuit connection to the T.S. There are settings on the T.S. to enable multiple sessions - and a key sequence to back-out of one and choose another. You might hit BREAK-ESC for example and be given a menu....it is quite similar to the concept of the ISN, but it needs to be programmed. No special software is required outside of that which your app requires, such as VT52/100/102/220/340, etc. -- +--------------------------------------------------------------------------+ | Carlo Milono: cmilono@netcom.apple.com or apple!netcom!cmilono | |"When a true genius appears in the world, you may know him by this sign, | |that the dunces are all in confederacy against him." - Jonathan Swift | +--------------------------------------------------------------------------+
mike@gordian.com (Michael Thomas) (03/29/91)
In article <1991Mar27.001042.283@bsu-ucs.uucp>, d001ucsac@bsu-ucs.uucp (Stephen P Kendall) writes: > > I'm connected to a university VAXcluster through a DECserver 500 (which > says it uses LAT V5.1) through an AT&T ISN network. The ISN network is not > a LAN in the usual sense; it connects to the terminal or PC through the > COM port (19.2 kBaud) rather than through special network hardware. > > The HELP menus on the DECserver mention an option to SET MULTISESSIONS ENABLE, > which then allows "multiple terminal sessions, each capable of a single LAT > service session" through the "TD/SMP protocol". This seems to imply that > with a "session management terminal" or a PC running suitable software, that > multiple simultaneous connections to the DECserver's services are possible. > > I have found no further reference to this capability, either in the grey wall > or the online docs. > > My question: > > 1) Is it possible to do this on a PC, given the hardware setup above > (not on a true LAN-style network, but connected to the DECserver > through a COM line)? > > 2) If so, with what software? > > -- This is indeed a murky subject with the DECservers, but maybe this will help. DEC's multiple session protocol (MSC) is intended to allow a "windowed" terminal to carry on conversations to multiple hosts through a single serial port. These "sessions" are distinct from the DECservers LAT connections, and really just spawn virtual jobs (sort of on the DECserver, really on the LANtronix box) that "Autoconnect" to the desired service/host. Multisessions rides on top of the normal flow controlled line (either XON/XOFF as in most DEC stuff, or RTS/CTS in other worlds) and only requires the following: 1) sacrosanct treatment of its control sequences which are of the form: DC4(^T) MSC-command FS (^\) 2) data must not be altered before it reaches the respective daemons (ie insertion of NULL's or anything else is a no-no) MSC is really a dippy network protocol with provisions for circuit creation, deletion, session flow control etc. Theoretically *any* serial line could support MSC, PC or otherwise providing it doesn't spew extranious stuff on the line. The only terminals that I'm aware of that support this capability are the VT330/340 and the VT420 as well as some (but not many) of the DEC knockoffs. I am not aware of any PC based package which deals with MSC but thats not something I ever look for. Such a package would have to be front ended by some PROCOMM or Kermit like that deals with the terminal emulation problems. My guess is that since it would require mutliple windows for the comm package, it probably doesn't exist since this would be a good deal of work (beyond just the MSC stuff). As for straight terminals off of your ISN network, there shouldn't be any problem providing your net doesn't diddle with the bits as they go by. Mike Thomas @ Gordian