0001 # SPDX-License-Identifier: GPL-2.0-only
0002 #
0003 # CCITT X.25 Packet Layer
0004 #
0005
0006 config X25
0007 tristate "CCITT X.25 Packet Layer"
0008 help
0009 X.25 is a set of standardized network protocols, similar in scope to
0010 frame relay; the one physical line from your box to the X.25 network
0011 entry point can carry several logical point-to-point connections
0012 (called "virtual circuits") to other computers connected to the X.25
0013 network. Governments, banks, and other organizations tend to use it
0014 to connect to each other or to form Wide Area Networks (WANs). Many
0015 countries have public X.25 networks. X.25 consists of two
0016 protocols: the higher level Packet Layer Protocol (PLP) (say Y here
0017 if you want that) and the lower level data link layer protocol LAPB
0018 (say Y to "LAPB Data Link Driver" below if you want that).
0019
0020 You can read more about X.25 at <https://www.sangoma.com/tutorials/x25/> and
0021 <http://docwiki.cisco.com/wiki/X.25>.
0022 Information about X.25 for Linux is contained in the files
0023 <file:Documentation/networking/x25.rst> and
0024 <file:Documentation/networking/x25-iface.rst>.
0025
0026 One connects to an X.25 network either with a dedicated network card
0027 using the X.21 protocol (not yet supported by Linux) or one can do
0028 X.25 over a standard telephone line using an ordinary modem (say Y
0029 to "X.25 async driver" below) or over Ethernet using an ordinary
0030 Ethernet card and the LAPB over Ethernet (say Y to "LAPB Data Link
0031 Driver" and "LAPB over Ethernet driver" below).
0032
0033 To compile this driver as a module, choose M here: the module
0034 will be called x25. If unsure, say N.
