from
The Free On-line Dictionary of Computing (8 July 2008)
Transport Layer Interface
TLI
Transport Level Interface
<networking, programming> (TLI, or "Transport Level
Interface") A {protocol}-independent interface for accessing
network facilities, modelled after the {ISO} {transport layer}
(level 4), that first appeared in {Unix SVR3}.
TLI is defined by {SVID} as transport mechanism for networking
interfaces, in preference to {sockets}, which are biased
toward {IP} and friends. A disavantage is that a process
cannot use read/write directly, but has to use backends using
{stdin} and {stdout} to communicate with the network
connection. TLI is implemented in SVR4 using the {STREAMS}
interface. It adds no new {system calls}, just a library,
libnsl_s.a. The major functions are t_open, t_bind,
t_connect, t_listen, t_accept, t_snd, t_rcv, read, write.
According to the {Solaris} t_open {man page}, XTI (X/OPEN
Transport Interface) evolved from TLI, and supports the TLI
{API} for compatibility, with some variations on semantics.
(1999-06-10)