Home/Support/Support Forum/How do I tell the PortServer to "redirect" telnet sessions to Port 1?
Welcome to Digi Forum, where you can ask questions and receive answers from other members of the community.

How do I tell the PortServer to "redirect" telnet sessions to Port 1?

0 votes
I'm trying to understand how to use my Digi Portserver TS 2 port MEI device so that I can connect to an old DOS based BBS over the network.

I have the PortServer plugged into my switch and I have no problem getting an IP address. I'm able to log in to the web interface and the telnet interface with no problem.

I have the RJ45 to DB9 cable that came with the PortServer running between Port 1 on the PortServer, and COM1 on the DOS computer. The BBS is up and running and ready to accept a "call" on COM1.

I've got into the web interface for the PortServer and have configured Port 1 in the Serial Ports section for Modem Emulation. (Though, I'm not sure if it should be Modem Emulation or something else. There's no real hardware modem involved. The BBS is set up to think of COM1 as a null modem. And I can connect to the BBS via null modem from another computer using a serial cross over cable.)

At this point, I don't know how to proceed so that I can connect to the BBS from other computers over the network. Obviously I don't just telnet to the IP address because that just connects me to the PortServer.

How do I tell the PortServer to "redirect" telnet sessions to Port 1 so that I pass through the PortServer transparently and just see the BBS log in screen?

Thank you.
asked Aug 13, 2014 in Other/Legacy by blixel New to the Community (5 points)

Please log in or register to answer this question.

2 Answers

+1 vote
You can use telnet or SSH to connect directly to the serial port. A step-by-step article is available for configuring reverse telnet which allows you to connect directly to the serial port of your device:


Hope this is useful.
answered Aug 13, 2014 by userid0 Veteran of the Digi Community (2,158 points)
I appreciate the response. I'll give this a try within the next couple of days and see how it goes.

This BBS supports up to 16 modems. I only have a 2 port Digi PortServer, but I'm thinking eventually I may get 4 or 8 ports. I saw hunt grouping as one of the options in the command line interface. I'm hoping that means I can set it up so that a person can telnet to the IP address, and it will automatically connect to the next available port?

So if someone is connected to Port 1 on the Digi PortServer and someone else telnet's in, the PortServer will automatically go to Port 2, Port 3, Port 4, and so on. Is that how it works?
+1 vote
You are correct, altip will allow you to set up a hunt group which will connect the user to the next available port:

answered Aug 14, 2014 by userid0 Veteran of the Digi Community (2,158 points)
Thanks. In looking that over, it looks perfect. It looks like I can set up a separate IP for the "modem pool" so that anyone telnet'ing to THAT address won't have to specify a special port. The PortServer will have its own IP address, and the "modem pool" will have another. That is ideal.

The last piece of the puzzle will be a serial port expander. In the old days, I had a Galactibox by Galacticomm. It was a chassis with 16 8-bit ISA slots. It came with a special card that you would plug into the computer, and then you would run a proprietary cable between their card and the chassis. The chassis basically turned 1 COM port into 16.

Since I'm not dealing with modems any more, what I really need is a serial port expander. Right now I only have a 2 port PortServer, but eventually I plan to get an 8 port PortServer. So I'll need a way to run the 8 port PortServer into the DOS PC.

Any suggestions for a 16-bit ISA serial expander to turn COM1 into 8 (or 16) serial ports? (I'd also be interested in a PCI suggestion as I may end up changing computers. I don't think PCI express is an option though. The serial port expander has to work with DOS.)