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How to set up a dial-in node for Internet access? (Being my own ISP)

kyodai

Experienced Member
Joined
Jan 26, 2011
Messages
467
Location
Kerpen, Germany
Well well, why make it easy when you can have it the hard way? So what i wanna do is setting up a dial-in modem node.

You remember when you had to use a modem to dial-in to your ISP via phone line to get to the internet? I wanna bring back the good old times.

So the idea is simple. My workstation (Internet user client) only has a standard 56k modem, my "ISP Server" is connected to the internet via Ethernet (DSL router) and has a 56k modem to receive calls (From my internet user client).

But after some research i couldn't find an easy way to do this. Maybe the easiest way would be to Install NT4 with RAS on the "ISP Server"?

Is there any other alternate solution to running a "Dial-In node"?


And bonus question: Can i directly connect the 2 modems of the server and client via a single RJ11 cable? Then how could i dial-in (I mean what phone number would i dial, just a single "0"?)?
 
A Viking DLE-200B, or other phone line simulator, could connect your modems with 2 cables. I've had one for over 20 years and it works great. These appear on ebay all the time. When the calling unit goes off hook the DLE-200B provides dial tone and ignores the number dialed, and provides ring voltage to the remote end. When the remote unit picks up the DLE-200B provides battery voltage so the two ends can communicate as though they are connected by a real telephone line. I believe either end can initiate the sequence.
 
Well including shipping and customs this would still be like 80 Dollar for me.

I found this interesting article. Not exactly an ISP, but good proof of concept that you can just connect 2 computers modems via a simple RJ11 cable and have some basic networking:

https://en.wikibooks.org/wiki/Transferring_Data_between_Standard_Dial-Up_Modems

The culprit here is that i don't just wanna use Hyper Terminal (Or some other Terminal program) to send/receive data via raw AT commands. While that is interesting I'd love to see any software that would offer TCP/IP over such a connection. I might look into Windows NT4/Win95 RAS capabilities, but if there are alternate solutions, ideas or comments then be sure to let me know.
 
Well including shipping and customs this would still be like 80 Dollar for me.

So find the local equivalent phone line simulator near you. There were tons of these used by all kinds of people in the 80's and 90's, but not as much any more.

I found this interesting article. Not exactly an ISP, but good proof of concept that you can just connect 2 computers modems via a simple RJ11 cable and have some basic networking:

https://en.wikibooks.org/wiki/Transferring_Data_between_Standard_Dial-Up_Modems

This may or may not work depending on the exact modems. The problem is that dial-up modems generally expect to see battery voltage from the CO, and it is unlikely that there will be any in this scenario. But it is possible that they might work anyway (I never tried it).

The culprit here is that i don't just wanna use Hyper Terminal (Or some other Terminal program) to send/receive data via raw AT commands. While that is interesting I'd love to see any software that would offer TCP/IP over such a connection. I might look into Windows NT4/Win95 RAS capabilities, but if there are alternate solutions, ideas or comments then be sure to let me know.

In the dial-up Internet era I wrote and sold software that allowed a 386-class PC with an appropriate ethernet card and packet driver to be used as a demand-dial (or dial-in) IP router with NAT. The user could script the modem control lines and AT commands as needed. Ancient evaluation version available here (don't bother to register it if you use it). You may even get this to work with an off-the-shelf dial-up (or dial backup) router, e.g. Rockwell NetHopper.

BTW - there is still a minor denial-of-service problem with my IPRoute software because I was no longer using or supporting it when I became aware of it: CVE-2001-1540
 
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Well not sure if i really need the phone line simulator. Thanks for the tip though, I'll keep it in mind if no other solutions work.

Hmm, yeah the voltage might be a problem, depending on the modem. But i have so many spare power supplies and i can prolly find a matching capacitor and resistor and jury rig the cable to have sufficient voltage.

That IP routing tool is an interesting idea. Don't think I'll use it, but it gave me the idea to just setup an old Windows 98 PC with PPP Dialup server and then simply use "WinRoute Pro". Actually WinRoute Pro is in a nutshell pretty much the same as your package, just with a nice GUI (Well windows...) and because of the Windows layer i could set it up for virtually every modem that works on Win98. OK, to be honest i always sucked with DOS, network cards and TCP/IP. I have had a few machiens running fine, but my memories of DOS, TCP/IP and network cards are just "headache". XD

Anyways, before i forget it - THANKS A LOT for your valuable feedback. Haven't tried anything yet, but I think I am already very close to becoming a new dial-up ISP... :) Ahhh i have to try out my IBM PC110 with its powerful 2400 baud modem XD
 
You can do what you want to accomplish with any old Linux/*BSD box. I was a fan of SLiRP ( https://en.wikipedia.org/wiki/Slirp ) back when shell accounts were often free but PPP accounts were not. Basically you bring up a SLIP/PPP connection by dialing into your box as usual (or over a direct serial link), and run `slirp` when you want to bring up the link.
 
You can do what you want to accomplish with any old Linux/*BSD box.

My concern was that kyodai seems to want to use a home-built circuit to supply battery voltage. This means there will never be dial tone or ring voltage, so the modem receiving the "call" will not answer without being explicitly told. I understand you can probably get the Linux/BSD box to force an answer in that case but I wasn't exactly sure how.
 
I've only tried this once, but it worked for me. I believe I used the exact circuit in the link above, with an old 9v wall wart instead of a battery. Had two systems talking via modems, but for my purposes I switched to a parallel connection as it was quicker.
 
way way way back in the day when I had an XT in the basement and the parents had a 486 upstairs I would use some unused pair in our telephone line to connect the modems together, I would atdt on the xt and frantically run upstairs and bang in ata before the modem downstairs gave up looking for a dialtone and they would handshake

more recently before I moved out of the apartment last year I had no need for a pots so I just disconnected the internal wiring from the outside world and used the phone jacks as low speed serial connections :evilgrin1:

(low speed being 19200 from across the apartment, 115200 from across the room)

now days I have a 4 port serial switch which goes into a wifi enabled pcduino (similar to a ras pi)
 
I don't think the missing dial tone will be a problem, even under windows you can force a blind dial. I could prolly even come up with some circuitry to emulate a dial tone, but i don't think it's necessary.

So far the devices i really wanna connect are a Lexicomp LC-8620, IBM PC-110 and my old Dreamcast console.
 
I've wanted to do a similar thing for a long time, including using a Linux machine to bridge the dialup connection to one of those online BBSes you can access via Telnet. Unfortunately for me (in Australia) any local line simulators that show up on eBay are priced well over $1000 so not really practical for a few minutes of fun. Shipping from the US is also prohibitively expensive so it's still one of those projects on the "maybe one day" list.

The other option I was looking at is one of those FXS PCI cards which are used in VoIP systems to allow you to plug your normal handset in and it provides all the voltages needed to make the handset think it's connected to a normal phone line. I'm not sure if you can get software that acts like a 56k modem on the FXS port but I can't think of any technical reason why it can't be done. Unfortunately those are somewhat pricey too. Only the FXO cards (connecting to an existing phone line, like a normal dialup modem does) tend to be cheap.
 
If you want to experiment with Asterisk (either directly on a Linux distro of your choice, or one of the pre-packaged ready to go Asterisk-specific distros), you can pick up a cheap Digium Wildcard like the TDM410, plug it into a Pentium 2 or better (I'm using a VIA C3 fanless Mini-ITX machine), and have four analog lines from which you can get real dialtone. You can then set up extensions to allow for real PBX dialing between your systems. Modems do work over these links (I've tried it), the trouble seems to be when you want to connect to a remote system over a VoIP connection.

You can pick up a TDM410 with FXS modules for under $50 if you wait around. In fact, there's one for sale in Australia at the moment, at $36 USD, on eBay. The TDM410 (or larger 8-line TDM800) allow mixing FXS and FXO modules, so if you decide to connect it to a POTS line, you can add a module in as needed.
 
I've wanted to do a similar thing for a long time, including using a Linux machine to bridge the dialup connection to one of those online BBSes you can access via Telnet. Unfortunately for me (in Australia) any local line simulators that show up on eBay are priced well over $1000 so not really practical for a few minutes of fun. Shipping from the US is also prohibitively expensive so it's still one of those projects on the "maybe one day" list.

The other option I was looking at is one of those FXS PCI cards which are used in VoIP systems to allow you to plug your normal handset in and it provides all the voltages needed to make the handset think it's connected to a normal phone line. I'm not sure if you can get software that acts like a 56k modem on the FXS port but I can't think of any technical reason why it can't be done. Unfortunately those are somewhat pricey too. Only the FXO cards (connecting to an existing phone line, like a normal dialup modem does) tend to be cheap.

As i said before - i don't think you need a line simulator, imho wasted money. If you need voltage on the phone line should depend on the modems you use, but putting a few stable volt on a line would cost you a power supply, a condensator and a resistor. Afaik not all modems need voltage on the phone line.

Blind dialing (Modem does not wait for a"free line" tone before dialing) should be avilable from most programs. If your program does not support that then an idea i had is to plug your phone cable between your initiating PC and your real phone line, so you get the "line ready" tone and instruct the modem to dial-in. Then when it initialized like "Ah the line is not busy lets start dialing" you quickly unplug the cable and stuff it into the server. =)


If you are super lazy and just want "a few minutes of fun" then bring your client to a neighbor, plug it into their real phone line and have the server plugged into your local phone socket, then you just let the client call your home phone number. Prolly won't cost much charges (1 bottle of Fosters for 20 minutes of fun!) and good enough for some cheap laughs.
 
As i said before - i don't think you need a line simulator, imho wasted money. If you need voltage on the phone line should depend on the modems you use, but putting a few stable volt on a line would cost you a power supply, a condensator and a resistor. Afaik not all modems need voltage on the phone line.

Blind dialing (Modem does not wait for a"free line" tone before dialing) should be avilable from most programs. If your program does not support that then an idea i had is to plug your phone cable between your initiating PC and your real phone line, so you get the "line ready" tone and instruct the modem to dial-in. Then when it initialized like "Ah the line is not busy lets start dialing" you quickly unplug the cable and stuff it into the server. =)

Blind dialling is not a problem. It doesn't require program support beyond being able to supply the right AT command to the modem. The problem is getting the modems to hear each other, and this requires the presence of something that resembles a real phone line. You can't plug two modems together directly as they cannot hear each other, however you can connect two modems to your own house phone line and instruct one to dial nothing ("ATD") and the other to answer ("ATA") and they will successfully connect, once the dial tone has gone away and the line has become silent (i.e. you are not making a phone call, but both modems are connected together via a real phone line.)

However if you don't have a POTS line connected to your house any more, then without a line simulator, it's like replacing a floppy drive with a USB stick - it works, but without the noise it's not the same. Sure a battery/resistor/etc. might get the job done, but it doesn't give you the full experience of the original process you remember so fondly. If you aren't fussed about the experience, the dialling process, and all that "ritual" then you might as well just use a direct serial connection or get a couple of network cards - they will do the job faster and with less hassle, no power supply needed.

But for those of us who want the original experience, we want to hear the dial tone as well :)
 
Depending on the modem, you can force one into answer mode without a dial tone. The one similarly set to originate mode will negotiate with the answering one. I used to do this with my USR Courier Dual Standards. I don't know if this works with non-USR modems.
 
Yep, issue "ATA" on the modem that should answer, and "ATD" on the other modem. They will both connect as if the ATD one dialled the other, but without issuing any DTMF tones or making any calls.

But this only works if both modems are plugged into a phone line (it can be the same line and even an inactive line, as long as there is voltage on the line.) You can do this by plugging a double-adapter into a phone line, and plugging the two modems into the double adapter. But as soon as you unplug the double adapter from the phone line the modems will disconnect, even though they are still connected together through the double adapter. It seems that at least the modems I have tested need the line voltage present or they can't "hear" each other.
 
Blind dialling is not a problem. It doesn't require program support beyond being able to supply the right AT command to the modem. The problem is getting the modems to hear each other, and this requires the presence of something that resembles a real phone line. You can't plug two modems together directly as they cannot hear each other, however you can connect two modems to your own house phone line and instruct one to dial nothing ("ATD") and the other to answer ("ATA") and they will successfully connect, once the dial tone has gone away and the line has become silent (i.e. you are not making a phone call, but both modems are connected together via a real phone line.)

However if you don't have a POTS line connected to your house any more, then without a line simulator, it's like replacing a floppy drive with a USB stick - it works, but without the noise it's not the same. Sure a battery/resistor/etc. might get the job done, but it doesn't give you the full experience of the original process you remember so fondly. If you aren't fussed about the experience, the dialling process, and all that "ritual" then you might as well just use a direct serial connection or get a couple of network cards - they will do the job faster and with less hassle, no power supply needed.

But for those of us who want the original experience, we want to hear the dial tone as well :)


If you just wanna hear a 425 hz tone then this youtube video was made for you...

https://www.youtube.com/watch?v=Paksm01yVSU

I'd like to have a line simulator, but I don't have so much money for it. I still have a normal POTS line, so i can dial up, even to an ISP or a BBS. But what i want is my own ISP server, I am indeed more into building that then into hearing dial tones, oh well maybe i just don't feel nostalgic enough today.
 
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