usr/contrib/xns/README

This directory contains the version of the UNIX XNS/Courier implementation
currently under development by JQJ@CORNELL.  It is still a test version.
This file last updated 30 Oct. 1985.

To install the XNS Courier package:

1/      install 4.3BSD, including support for XNS protocols by K. Sklower.
        The Courier system is known to work on VAXes and Gould Powernode
        systems running 4.3BSD.  It probably works on a SUN with XNS
        support.
3/      edit the file ./morexnslib/ch/clearinghouse.addresses to contain
        the address of a local clearinghouse and a list of the domains
        served.  Some programs in this package use the first domain in the
        list as a default if no domain is specified, e.g. "gaptelnet foo"
        defaults domain and organization on foo based on this file.
4/      do ``make install'' on this directory.  Note that you MUST use
        ``make install'', and will probably need to be logged in as root.
        A simple ``make'' won't do, since some things require previous
        installation of earlier things.
5/      edit /etc/rc.local to automatically run /etc/xnscourierd at system
        startup.  This is the daemon that listens for incoming Courier
        connections.  When it receives a connection, it looks up the remote
        program in /usr/new/lib/xnscourier/Courierservices and runs that
        program.

Problems:
1/      The compiler is incomplete:  it does not handle forward references,
        recursive declarations, constants containing a non-trivial CHOICE,
        or recursive DEPENDencies.
2/      The client runtimes are incomplete:  they do not correctly handle BDT
        Abort messages; they require a static file (clearinghouse.addresses)
        containing a local Clearinghouse rather than performing an expanding-
        ring search.
3/      The server runtimes are incompletely tested.
4/      Providing Courier services is quite expensive.  In general, at least
        one process per SPP connection is required.

On the other hand, the package is adequate for writing non-trivial Courier
client and server programs.  Of particular note are the example subdirectories
print, gap, and filing, which contain Courier applications for (1) printing
an Interpress master on a Xerox printer, (2) telnet (chat, aka GAP) from Unix
to file servers or from Star to Unix, (3) an ftp-like interface to filing,
allowing a Unix user to store and retrieve files from a Xerox file server.

Note that in order to use XNS Chat to your Unix system you will need to
register the Unix system with the Xerox Clearinghouse.  To do so, use the
program registerhost contained on the examples/ch directory.