Staging

Becoming your own dial-up ISP in 2019

Required hardware:

• A hardware modem (not a software modem/winmodem, must be the real deal)
• A computer to install linux on to talk to the a modem (Can be anything that a modern linux distribution will run on. Raspberry Pi, Pi clone, x86 machine, etc)
• A client device (windows 9x PC for example) with a modem
• Some form of PSTN to connect the two modems

The exact hardware I’ve used

• Generic x86_64 PC running Debian 9.5 x86_64
• Matrix “MX Modem” (more on this later)
• USB to RS232 serial adapter (DE-9) to connect to the modem (Must support hardware flow control)
• DE-9 to DB-25 serial adapter
• Linksys PAP2T analog telephone adapter (ATA)
• x86 based Windows 95 PC with a US Robotics Sportster 28800 ISA modem

Software used

• Debian 9.5 x86_64
• PPP
• getty
• Asterisk

Preparing the dial-in-server

1. Install Debian/Ubuntu/Raspbian per the usual methods (not covered here)
2. Update to latest packages and reboot if required
   

   sudo apt-get update
   sudo apt-get upgrade
   sudo reboot

3. Connect USB to RS232 adapter and confirm it shows up as /dev/ttyUSBXXX

In my case it presents as /dev/ttyUSB0

My serial adapter is a “ID 1a86:7523 QinHeng Electronics HL-340 USB-Serial adapter” Full lsusb -v output: (in gedit) Install ppp (and getty if your distro doesn’t have it be default) sudo apt-get install ppp Many of the old guides were written when inittab was still around but its 2019 and systemd has taken over. We need to create a systemd service for mgetty Edit /lib/systemd/system/mgetty.service