In
computer networking
A computer network is a set of computers sharing resources located on or provided by network nodes. The computers use common communication protocols over digital interconnections to communicate with each other. These interconnections are ...
, the Transport Layer Interface (TLI) was the networking
API provided by
AT&T
AT&T Inc. is an American multinational telecommunications holding company headquartered at Whitacre Tower in Downtown Dallas, Texas. It is the world's largest telecommunications company by revenue and the third largest provider of mobile ...
UNIX System V
Unix System V (pronounced: "System Five") is one of the first commercial versions of the Unix operating system. It was originally developed by AT&T and first released in 1983. Four major versions of System V were released, numbered 1, 2, 3, an ...
Release 3 (SVR3) in 1987 and continued into Release 4 (SVR4). TLI was the System V counterpart to the
BSD sockets programming interface, which was also provided in
UNIX System V
Unix System V (pronounced: "System Five") is one of the first commercial versions of the Unix operating system. It was originally developed by AT&T and first released in 1983. Four major versions of System V were released, numbered 1, 2, 3, an ...
Release 4 (SVR4). TLI was later standardized as XTI, the
X/Open Transport Interface.
TLI and Sockets
It was originally expected that the
OSI protocols would supersede TCP/IP, thus TLI is designed from an
OSI model-oriented viewpoint, corresponding to the OSI
transport layer
In computer networking, the transport layer is a conceptual division of methods in the layered architecture of protocols in the network stack in the Internet protocol suite and the OSI model. The protocols of this layer provide end-to-e ...
. Otherwise, TLI looks similar, API-wise, to sockets.
TLI and XTI were widely used (?) and, up to UNIX 98, may have been preferred over the POSIX Sockets 5API
with respect to existing standards. However, it was clear at least since the early 1990s that the Berkeley Socket interface would ultimately prevail. TLI and XTI are still supported in SVR4-derived
operating systems
An operating system (OS) is system software that manages computer hardware, software resources, and provides common services for computer programs.
Time-sharing operating systems schedule tasks for efficient use of the system and may also in ...
and operating systems conforming to branded UNIX (UNIX 95, UNIX 98 and UNIX 03 Single UNIX Specifications) such as
Solaris and
AIX
Aix or AIX may refer to:
Computing
* AIX, a line of IBM computer operating systems
*An Alternate Index, for a Virtual Storage Access Method Key Sequenced Data Set
* Athens Internet Exchange, a European Internet exchange point
Places Belgiu ...
(as well as the
classic Mac OS
Mac OS (originally System Software; retronym: Classic Mac OS) is the series of operating systems developed for the Macintosh family of personal computers by Apple Computer from 1984 to 2001, starting with System 1 and ending with Mac OS 9. ...
, in the form of
Open Transport
Open Transport was the name given by Apple Inc. to its implementation of the Unix-originated System V STREAMS networking stack. Based on code licensed from Mentat's Portable Streams product, Open Transport was built to provide the classic Mac OS ...
). Under UNIX 95 (XPG4) and UNIX 98 (XPG5.2), XTI was the preferred and recommended supported API for new transport protocols.
As a result of deliberations by the Austin Group with the goal of bringing flavors of UNIX that do not provide
STREAMS
A stream is a continuous body of surface water flowing within the bed and banks of a channel. Depending on its location or certain characteristics, a stream may be referred to by a variety of local or regional names. Long large streams a ...
, such as
BSD and
Linux
Linux ( or ) is a family of open-source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically packaged as a Linux distribution, whi ...
, under the Single UNIX Specification, the UNIX 03 Single UNIX Specification both declares
STREAMS
A stream is a continuous body of surface water flowing within the bed and banks of a channel. Depending on its location or certain characteristics, a stream may be referred to by a variety of local or regional names. Long large streams a ...
as optional, and declares POSIX Sockets as the preferred API for new transport protocols.
See also
*
X/Open Transport Interface, formally standardized successor to TLI.
*
X/Open Portability Guide, the predecessor to
POSIX
The Portable Operating System Interface (POSIX) is a family of standards specified by the IEEE Computer Society for maintaining compatibility between operating systems. POSIX defines both the system- and user-level application programming in ...
*
Computer networking
A computer network is a set of computers sharing resources located on or provided by network nodes. The computers use common communication protocols over digital interconnections to communicate with each other. These interconnections are ...
, outlining the major networking protocols
Notes
References
*
*
*
*
*
*
*
*
*
*
*{{Cite document
, first=Steve
, last=Zucker
, author2=Kari Karhi
, publisher=SunSoft
, location=Mountain View, CA
, title=System V Application Binary Interface—PowerPc Processor Supplement
, year=1995
, orig-year=1993
External links
The Open Group's XTI standardExample client-server application working on Solaris and Linux
Application programming interfaces