summaryrefslogtreecommitdiffstats
path: root/Documentation/isdn/README.x25
diff options
context:
space:
mode:
Diffstat (limited to 'Documentation/isdn/README.x25')
-rw-r--r--Documentation/isdn/README.x25184
1 files changed, 0 insertions, 184 deletions
diff --git a/Documentation/isdn/README.x25 b/Documentation/isdn/README.x25
deleted file mode 100644
index e561a77..0000000
--- a/Documentation/isdn/README.x25
+++ /dev/null
@@ -1,184 +0,0 @@
-
-X.25 support within isdn4linux
-==============================
-
-This is alpha/beta test code. Use it completely at your own risk.
-As new versions appear, the stuff described here might suddenly change
-or become invalid without notice.
-
-Keep in mind:
-
-You are using several new parts of the 2.2.x kernel series which
-have not been tested in a large scale. Therefore, you might encounter
-more bugs as usual.
-
-- If you connect to an X.25 neighbour not operated by yourself, ASK the
- other side first. Be prepared that bugs in the protocol implementation
- might result in problems.
-
-- This implementation has never wiped out my whole hard disk yet. But as
- this is experimental code, don't blame me if that happened to you.
- Backing up important data will never harm.
-
-- Monitor your isdn connections while using this software. This should
- prevent you from undesired phone bills in case of driver problems.
-
-
-
-
-How to configure the kernel
-===========================
-
-The ITU-T (former CCITT) X.25 network protocol layer has been implemented
-in the Linux source tree since version 2.1.16. The isdn subsystem might be
-useful to run X.25 on top of ISDN. If you want to try it, select
-
- "CCITT X.25 Packet Layer"
-
-from the networking options as well as
-
- "ISDN Support" and "X.25 PLP on Top of ISDN"
-
-from the ISDN subsystem options when you configure your kernel for
-compilation. You currently also need to enable
-"Prompt for development and/or incomplete code/drivers" from the
-"Code maturity level options" menu. For the x25trace utility to work
-you also need to enable "Packet socket".
-
-For local testing it is also recommended to enable the isdnloop driver
-from the isdn subsystem's configuration menu.
-
-For testing, it is recommended that all isdn drivers and the X.25 PLP
-protocol are compiled as loadable modules. Like this, you can recover
-from certain errors by simply unloading and reloading the modules.
-
-
-
-What's it for? How to use it?
-=============================
-
-X.25 on top of isdn might be useful with two different scenarios:
-
-- You might want to access a public X.25 data network from your Linux box.
- You can use i4l if you were physically connected to the X.25 switch
- by an ISDN B-channel (leased line as well as dial up connection should
- work).
-
- This corresponds to ITU-T recommendation X.31 Case A (circuit-mode
- access to PSPDN [packet switched public data network]).
-
- NOTE: X.31 also covers a Case B (access to PSPDN via virtual
- circuit / packet mode service). The latter mode (which in theory
- also allows using the D-channel) is not supported by isdn4linux.
- It should however be possible to establish such packet mode connections
- with certain active isdn cards provided that the firmware supports X.31
- and the driver exports this functionality to the user. Currently,
- the AVM B1 driver is the only driver which does so. (It should be
- possible to access D-channel X.31 with active AVM cards using the
- CAPI interface of the AVM-B1 driver).
-
-- Or you might want to operate certain ISDN teleservices on your linux
- box. A lot of those teleservices run on top of the ISO-8208
- (DTE-DTE mode) network layer protocol. ISO-8208 is essentially the
- same as ITU-T X.25.
-
- Popular candidates of such teleservices are EUROfile transfer or any
- teleservice applying ITU-T recommendation T.90.
-
-To use the X.25 protocol on top of isdn, just create an isdn network
-interface as usual, configure your own and/or peer's ISDN numbers,
-and choose x25iface encapsulation by
-
- isdnctrl encap <iface-name> x25iface.
-
-Once encap is set like this, the device can be used by the X.25 packet layer.
-
-All the stuff needed for X.25 is implemented inside the isdn link
-level (mainly isdn_net.c and some new source files). Thus, it should
-work with every existing HL driver. I was able to successfully open X.25
-connections on top of the isdnloop driver and the hisax driver.
-"x25iface"-encapsulation bypasses demand dialing. Dialing will be
-initiated when the upper (X.25 packet) layer requests the lapb datalink to
-be established. But hangup timeout is still active. Whenever a hangup
-occurs, all existing X.25 connections on that link will be cleared
-It is recommended to use sufficiently large hangup-timeouts for the
-isdn interfaces.
-
-
-In order to set up a conforming protocol stack you also need to
-specify the proper l2_prot parameter:
-
-To operate in ISO-8208 X.25 DTE-DTE mode, use
-
- isdnctrl l2_prot <iface-name> x75i
-
-To access an X.25 network switch via isdn (your linux box is the DTE), use
-
- isdnctrl l2_prot <iface-name> x25dte
-
-To mimic an X.25 network switch (DCE side of the connection), use
-
- isdnctrl l2_prot <iface-name> x25dce
-
-However, x25dte or x25dce is currently not supported by any real HL
-level driver. The main difference between x75i and x25dte/dce is that
-x25d[tc]e uses fixed lap_b addresses. With x75i, the side which
-initiates the isdn connection uses the DTE's lap_b address while the
-called side used the DCE's lap_b address. Thus, l2_prot x75i might
-probably work if you access a public X.25 network as long as the
-corresponding isdn connection is set up by you. At least one test
-was successful to connect via isdn4linux to an X.25 switch using this
-trick. At the switch side, a terminal adapter X.21 was used to connect
-it to the isdn.
-
-
-How to set up a test installation?
-==================================
-
-To test X.25 on top of isdn, you need to get
-
-- a recent version of the "isdnctrl" program that supports setting the new
- X.25 specific parameters.
-
-- the x25-utils-2.X package from
- ftp://ftp.hes.iki.fi/pub/ham/linux/ax25/x25utils-*
- (don't confuse the x25-utils with the ax25-utils)
-
-- an application program that uses linux PF_X25 sockets (some are
- contained in the x25-util package).
-
-Before compiling the user level utilities make sure that the compiler/
-preprocessor will fetch the proper kernel header files of this kernel
-source tree. Either make /usr/include/linux a symbolic link pointing to
-this kernel's include/linux directory or set the appropriate compiler flags.
-
-When all drivers and interfaces are loaded and configured you need to
-ifconfig the network interfaces up and add X.25-routes to them. Use
-the usual ifconfig tool.
-
-ifconfig <iface-name> up
-
-But a special x25route tool (distributed with the x25-util package)
-is needed to set up X.25 routes. I.e.
-
-x25route add 01 <iface-name>
-
-will cause all x.25 connections to the destination X.25-address
-"01" to be routed to your created isdn network interface.
-
-There are currently no real X.25 applications available. However, for
-tests, the x25-utils package contains a modified version of telnet
-and telnetd that uses X.25 sockets instead of tcp/ip sockets. You can
-use those for your first tests. Furthermore, you might check
-ftp://ftp.hamburg.pop.de/pub/LOCAL/linux/i4l-eft/ which contains some
-alpha-test implementation ("eftp4linux") of the EUROfile transfer
-protocol.
-
-The scripts distributed with the eftp4linux test releases might also
-provide useful examples for setting up X.25 on top of isdn.
-
-The x25-utility package also contains an x25trace tool that can be
-used to monitor X.25 packets received by the network interfaces.
-The /proc/net/x25* files also contain useful information.
-
-- Henner