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the AS/400 wireless LAN adapter and remote stations. Remote stations can be PTCs that are running
5250 emulation or LAN-connected systems that are equipped with compatible wireless adapters. There are
other implementations of wireless LAN.
Wide area network standards
A wide area network (WAN) is a data communications network designed to serve an area of hundreds or
thousands of miles--for example, public and private packet-switching networks, and national telephone
networks.
These topics introduce the types of wide area networks that are supported by the AS/400 system:
v
Asynchronous communications
v
Binary synchronous communications
v
Frame relay
v
Integrated services digital network
v
Synchronous data link control network
v
X.25 network
v
X.21 network
Asynchronous communications
OS/400 asynchronous communications support allows an AS/400 application program to exchange data
with a remote system or device using either an asynchronous (start-stop) or X.25 line. AS/400 application
programs can be written in ILE COBOL/400, ILE RPG/400, ILE C/400, or FORTRAN/400 languages.
Asynchronous communications support includes file transfer support (also used with other communications
types) and interactive terminal facility (ITF). Asynchronous communications support provides
program-to-program and program-to-device communications between systems that use asynchronous
(start-stop) or X.25 lines. For X.25 lines, it also supplies an integrated packet assembler/disassembler
(PAD) (1) that follows CCITT recommendations X.3, X.28, and X.29.
Asynchronous communications support allows you to send data to and receive data from a remote
program or device attached by either an asynchronous (start-stop) or an X.25 line. Your application
program must provide the data stream required by the remote device. Asynchronous communications
support packages your data stream in either a start-stop format or within X.25 data packets.
Binary synchronous communications
(BSC) is a data communications line protocol that uses a standard set of transmission control characters
and control character sequences to send binary-coded data over a communications line. Binary
synchronous communications equivalence link (BSCEL) support is the intersystem communications
function (ICF) support on the AS/400 system that provides binary synchronous communications with a
remote system or device. BSCEL also supplies online and batch communications between application
programs on different BSC systems. AS/400 application programs can be written in the Integrated
Language Environment (ILE) C/400*, ILE COBOL/400*, ILE FORTRAN/400*, or ILE RPG/400*
programming languages.
Frame relay networks
Frame relay is a protocol that defines how frames are routed through a fast-packet network based on the
address field in the frame. Frame relay takes advantage of the reliability of data communications networks
to minimize the error checking done by the network nodes. This provides a packet-switching protocol
similar to, but much faster than, X.25. The high speed that can be obtained through frame-relay networks
makes it well suited for wide area network (WAN) connectivity. Frame relay is commonly used to connect
two or more LAN bridges over large distances.
The AS/400 system supports these frame-relay network connections:
Chapter 10. Common networking standards
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