Running Linux, 5th Edition - Matthias Kalle Dalheimer [259]
Follow these two steps to set up dial-up PPP over ISDN:
Configure your ISDN hardware.
Configure and start the PPP daemon and change the routing table to use your ISDN line.
We cover those steps in the next sections.
Configuring Your ISDN Hardware
The first step involves making your ISDN board accessible to the kernel. As with any other hardware board, you need a device driver that is configured with the correct parameters for your board.
Linux supports a large number of ISDN hardware boards. We cannot cover every single board here, but the procedure is more or less the same for each one. Reading the documentation for your specific card in the directory Documentation/isdn in the Linux kernel sources will help you a lot if your board is not covered here.
We will concentrate here on boards that use the so-called HiSax driver. This device driver works with almost all cards that use the Siemens HSCX chipset (and thus with most passive cards available on the market today). That includes, for instance, the USR Sportster internal TA and the well-known Teles, ELSA, and Fritz boards. Other boards are similarly configured. Even some active cards are supported by Linux, including the well-known AVM B1 and the IBM Active 2000 ISDN card.
The first thing you need to do is configure the kernel so that it includes ISDN support. We advise you to compile everything ISDN-related as modules, especially while you are experimenting with setting it up. You will need the following modules:
ISDN support.
Support for synchronous PPP.
One device driver module for your hardware. If you pick the HiSax driver, you will also have to specify which specific brand of ISDN card you have and which ISDN protocol you want to use. The latter is almost certainly EURO/DSS1 in Europe—unless you live in Germany and have had your ISDN for a long time, in which case it might be 1TR6—and US NI1 in the U.S. If you live elsewhere, or are in doubt, ask your phone company.
Compile and install the modules as described in Chapter 18. Now you are ready to configure your ISDN hardware. Some distributions, such as SUSE, make setting up ISDN lines very easy and comfortable. We cover the hard way here in case your distribution is not so user-friendly, the automatic configuration does not work, or you simply want to know what is going on behind the scenes.
Now you need to load the device driver module using modprobe. This will automatically load the other modules as well. All the device driver modules accept a number of module parameters; the hisax module accepts, among others, the following:
id= boardid
Sets an identifier for the ISDN board. You can pick any name you like here, but you cannot have the same identifier for more than one board in your system.
type= boardtype
Specifies the exact board brand and type. For example, a value of 16 for boardtype selects the support for the USR Sportster internal TA. See Documentation/isdn/README.hisax in the kernel sources for the full list of board types.
protocol= protocoltype
Selects an ISDN subprotocol. Valid values for protocoltype are 1 for the old German 1TR6 protocol, 2 for the common EDSS1 (so-called Euro ISDN), and 3 for leased lines.
irq= irqno
Specifies the interrupt line to use. Not all boards need this.
io= addr
Specifies the I/O address to use. Not all boards need this. Some boards need two I/O addresses. In this case, the parameters to use are io0 and io1.
For example, the following command loads the HiSax driver for use with a Teles 16.3 board, Euro ISDN, IO address 0x280, and IRQ line 10 (a very common case):
tigger # modprobe hisax type=3 protocol=2 io=0x280 irq=10
Please see Documentation/isdn/README.HiSax or the equivalent file for your hardware for more information.
This module is not much of a talker; if there is no output from the modprobe command, it