HP Rp7410 BSD Sockets Interface Programmer's Guide - Page 17

BSD Sockets Concepts Introduction Introduction This guide describes the steps involved in establishing and using BSD Sockets connections. It also describes the protocols you must use and how the BSD Sockets system calls interact. The details of each system call are described in the corresponding man pages. Key Terms and Concepts For a basic understanding of BSD Sockets and its general model, you should review the following terms and definitions. address family addressing association The address format used to interpret addresses specified in socket operations. The internet address family (AF_INET) and the Berkeley UNIX Domain address family (AF_UNIX) are supported. A means of labeling a socket so that it is distinguishable from other sockets on a host. A BSD Sockets connection is defined by an association. An AF_INET association contains the (protocol, local address, local port, remote address, remote port)-tuple. An AF_UNIX association contains the (protocol, local address, peer address)-tuple. Associations must be unique; duplicate associations on the same host cannot exist. The tuple is created when the local and remote socket addresses are bound and connected. This means that the association is created in two steps, and there is a chance that two potential associations could be alike between steps. The host prevents duplicate associations by checking for uniqueness of the tuple at connection time, and reporting an error if the tuple is not unique. Chapter 1 17