59.16. Summary

Internet domain sockets allow applications on different hosts to communicate via a TCP/IP network. An Internet domain socket address consists of an IP address and a port number. In IPv4, an IP address is a 32-bit number; in IPv6, it is a 128-bit number. Internet domain datagram sockets operate over UDP, providing connectionless, unreliable, message-oriented communication. Internet domain stream sockets operate over TCP, and provide a reliable, bidirectional, byte-stream communication channel between two connected applications.

Different computer architectures use different conventions for representing data types. For example, integers may be stored in little-endian or big-endian form, and different computers may use different numbers of bytes to represent numeric types such as int or long. These differences mean that we need to employ some architecture-independent representation when transferring data between heterogeneous machines connected via a network. We noted that various marshalling standards exist to deal this problem, and also described a simple solution used by many applications: encoding all transmitted data in text form, with fields delimited by a designated character (usually a newline).