TCP/IP Services supports serial connections using the following
    protocols:

    o  Serial Line IP (SLIP) and Compressed SLIP (CSLIP) protocols

       Sends datagrams across the serial line as a series of bytes,
       using special characters to mark when a series of bytes should
       be grouped together

    o  Point-to-Point Protocol (PPP) (Alpha only)

       Uses a frame format that includes a field to identify the
       protocol (for example: IP or OSI).

    One of the largest applications for SLIP and PPP is dialup
    access.

    With PPP, you can establish a dynamic IP network connection over
    a serial line without the extensive use of additional router or
    server hardware. PPP ensures interoperability between systems
    from a wide variety of vendors.

    Because SLIP has been in use for a longer period of time,
    it is available for most terminal servers and in most PC
    implementations of TCP/IP. CSLIP provides header compression
    to improve packet throughput, which is especially beneficial for
    small packets.

    For either SLIP or PPP connections, a host can function as a
    dialup provider (server) to respond to incoming connection
    requests. Or, a host can function as a client dialing in to a
    dialup provider.

    Setting up your OpenVMS host as a dialup provider or client
    involves the following tasks:

    o  Installing the appropriate virtual terminal driver

    o  Configuring the interface for serial line connections
       (optional for clients)

    o  Configuring your modem

    o  Setting up an asynchronous port for modem connections

    o  Enabling IP forwarding and dynamic routing (dialup provider
       only)

    o  Initiating a connection (client only)