TLI was first introduced in the late 1980s with the release of AT&T UNIX System V Rel. 3.
TLI is fully conformant with the ISO transport service definition. TLI can support both TCP and ISO transport protocols as well as other transport protocols.
Although most recent distributions of UNIX support both Sockets and TLI, TLI is considered the preferred interface by many vendors. UNIX System V Rel. 4 and SUN's Solaris 2.x consider TLI the preferred Transport Interface.
Although both TLI and Sockets are supported in Novell's Netware, TLI is considered the preferred interface by Novell.