A socket is a fundamental building block for developing communication applications. A socket forms a communication endpoint. A name can be assigned to it, via which the socket can be accessed and addressed.
Each socket is of a specific type and has at least one associated process. Several associated processes can use the same socket and a process can also have connections to several sockets.
A socket belongs to a specific communications domain. A communication domain combines address families and protocol families. An address family includes addresses with the same address structure. A protocol family defines a set of protocols which implement the socket types in the domain. The purpose of the communication domains is to summarize common properties of processes that communicate via sockets.
The socket interface in BS2000 supports the Internet communications domains AF_INET and AF_INET6, and in the local host communications domain AF_UNIX.
There are various socket types with different communications characteristics. Two different socket types are currently supported:
stream sockets
datagram sockets