tcp(7)                              CLIX                              tcp(7)



  NAME

    tcp - Internet Transmission Control protocol

  DESCRIPTION

    The Transmission Control Protocol (TCP) provides reliable, flow-
    controlled, two-way transmission of data.  It is a byte-stream protocol
    used to support the sock_stream abstraction.  TCP uses the standard
    Internet address format and provides a per-host collection of port
    addresses.  Thus, each address is composed of an Internet address
    specifying the host and network, with a specific TCP port on the host
    identifying the peer entity.

    Sockets using the TCP protocol are either active or passive.  Active
    sockets initiate connections to passive sockets.  By default TCP sockets
    are created active; to create a passive socket the listen() function must
    be used after binding the socket with the bind() function.  Only passive
    sockets may use the accept() call to accept incoming connections.  Only
    active sockets may use the connect() call to initiate connections.

    Passive sockets may underspecify their location to match incoming
    connection requests from multiple networks.  This technique, termed
    wildcard addressing, allows a single server to provide service to clients
    on multiple networks.  To create a socket that listens on all networks,
    the user must bind() the Internet address INADDR_ANY.  The TCP port may
    still be specified at this time; if the port is not specified, the system
    will assign one.  Once a connection has been established, the socket's
    address is fixed by the peer entity's location.   The address assigned the
    socket is the address associated with the network interface through which
    packets are being transmitted and received.  Normally, this address
    corresponds to the peer entity's network.

  RELATED INFORMATION

    Functions:  accept(2), bind(2), connect(2), listen(2)

    Files:  inet(7), ip(7), intro(7)
















  2/94 - Intergraph Corporation                                              1