Chapter 4, Developing applications over IPX/SPX using TLI
Sequence Packet Exchange (SPX)

Sequence Packet Exchange (SPX)

SPX is a connection-based, reliable, sequenced transport protocol which provides:

guaranteed packet delivery
ensuring that packets are received in order by the destination endpoint

flow control
regulating the speed at which packets are sent and received by both the sending and receiving processes

The TLI (Transport Layer Interface) library provides routines with which to access SPX. SPX supports the following calls from the TLI library:

t_accept
accept a connect request

t_alloc
allocate a library structure

t_bind
bind an address to a transport endpoint

t_close
close a transport endpoint

t_connect
establish a connection with another transport user

t_error
produce an error message

t_free
free a library structure

t_getinfo
get protocol-specific service information

t_getstate
get the current state

t_listen
listen for a connect request

t_look
look at the current event on a transport endpoint 

t_open
establish a transport endpoint

t_optmgmt
manage options for a transport endpoint 

t_rcv
receive data or expedited data sent over a connection

t_rcvdis
retrieve information from disconnect

t_snd
send data or expedited data over a connection

t_snddis
send user-initiated disconnect request

t_sync
synchronize transport library

t_unbind
disable a transport endpoint
``Using the SPX protocol'' describes how to use these routines to access SPX.

The structures used by the TLI interface to SPX are: