A-Shell includes three general-purpose socket routines, TCPCLI, TCPSRV, and TCPX. TCPCLI and TCPSRV were the original routines, designed specifically for the client and server ends of a connection, respectively. TCPX is the new version (as of Build 855), combining and extending the features, and is preferred for new programming. With these, you can create or interface to most kinds of TCP based socket services. Since the subroutines are already documented, we will instead go on to discuss higher level considerations.