spp(7)                              CLIX                              spp(7)



  NAME

    spp - Xerox Sequenced Packet protocol

  SYNOPSIS

    #include <sys/socket.h>

    #include <netns/ns.h>

    socket(AF_NS, SOCK_STREAM, 0)

  DESCRIPTION

    The Sequenced Packet Protocol (SPP) provides reliable, flow-controlled,
    two-way transmission of data.  It is a byte-stream protocol used to
    support the sock_stream abstraction.  SPP uses the standard ns address
    formats.

    Sockets using the SPP protocol are either active or passive.  Active
    sockets initiate connections to passive sockets.  By default, SPP sockets
    are created active; to create a passive socket, the user must listen()
    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 service clients on multiple
    networks.  To create a socket that listens on all networks, the user must
    bind() an ns address of all zeros.  The SPP 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 to 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.

    Packets received with the attention bit sent are interpreted as out of
    band data.  Data sent with send(..., ..., ..., MSG_OOB) causes the
    attention bit to be set.

  RELATED INFORMATION

    Files: ns(7B), intro(7B)

    Section 2 reference manual entries







  2/94 - Intergraph Corporation                                              1