Terminal server

[Sunil_uk]

Thank you, I understood that,

But when I am trying to create a sessionfrom another system I am getting a time out error.

I tried tlenet create_session.

already one session I ahve created on another system as TNA1: and is showing on line.

DO I need to manully delete the session every time before creating the other one?.

Thank you

Sunil

[Volker Halle]

Sunil,

it works the same way as with LAT. You can only have ONE existing session to a terminal server port at any time (either with using LAT or with using TELNET protocol).

If your LAT application only establishes the LAT session to the port to output a message and then disconnects (as e.g. the LATSYM print symbiont will do), you would have to do the same with TELNET.

LAT connects would also be queued on the terminal server and then automatically completed, when the current connection is finished. This does NOT work with TCPIP.

Volker.

[Sunil_uk]

Thnak you,
I have triplicated system, where in one system will be the duty one and will be sending data to the telenet port cretaed.
But if this system goes down one of the other system will become duty and will stert sending the data. there is a pascal program running which does the data tarnsmission. But defining and creating the session will be done by VMS. and At a time only one session will be active..but the channel should be avalable for the other system, if there is failure on the first systm

Thank you
sunil

[Volker Halle]

Sunil,

with LAT, this is more transparent, as the connection to the terminal server port will be established, once you start the first write to the LTA device.

With TELNET CREATE_SESSION, the IP session is created immediately, so you can't have all 3 systems create this session at the same time.

It may be possible to use:

TELNET> CREATE_SESSION /TIMEOUT=(NOIDLE, RECONNECTION=nn)

Creates a device that disconnects on deassignment and reconnects when data is written to it.

I can't test this, but I would assume, that you should be able to do:

$ TELNET/CREATE_SESSION /TIMEOUT=(NOIDLE, RECONNECTION=1) server-ip server-port
$ OPEN/READ/WRITE x TNAx:
$ WRITE x "Starting"
$ CLOSE x

and then the TELNET-session to the terminal-server-port should be disconnected (due to the implicit $DASSGN by the CLOSE). After these commands, you might be able to issue these same commands on the other systems.

Volker.

[Sunil_uk]

Hi

The said option timeout is not avaialble in telenet/create_session.

Thank you

Sunil

[Volker Halle]

Sunil,

the availability of the /TIMEOUT option will depened on your version of UCX or TCPIP, e.g. UCX V4.2 on VAX does not have this option.

Volker.

[Sunil_uk]

Thank you


Sunil

[Sunil_uk]

I have created multiple telnet listener on port 1 (like 2001, 2002 and 2003).is it possible with any option to have three sessions from three different systems?.


Thanks Sunil

[Volker Halle]

Sunil,

as said before, it's my understanding, that you can only have ONE session to a DECserver port from any system at the same time (be it with LAT or TCPIP).

It 'seems' to work with LAT, as the LAT session is NOT established UNTIL the first WRITE operation to the LTA201: device is issued !

Your version of UCX creates the TELNET session immediately when executing the TELNET/CREATE_SESSION command, this fails on the 2nd and 3rd system, if the first system has already established a session to that port.

As a workaround, you might have to try the TELNET/CREATE_SESSION command on your standby nodes in a loop with an appropriate WAIT, if you get a device timeout. That way, you'll know, that once the TELNET/CREATE_SESSION succeeds, this node is the one with the connection established and ready to write to the display device...

Or - if the stand-by nodes KNOW when to become active - just issue the TELNET/CREATE_SESSION at that time, when you know that the original node has failed.

Volker.

[Jan van den Ende]

Sunil ( & Volker)

I have MULTISESSION ENABLE set, and I am using ONE VT520 to (up to) 8 sessions on ONE port.
But: NOT to predefined ports.

I do not know if this is usefull for your requirements; if yes, then I will gladly find out the setup and post it.

Proost.

Have one on me.

jpe