DNS-COM-AWNS-PING 1.0

CONTENTS
    INTRODUCTION
    MANIFEST
    INSTALL

INTRODUCTION

This is an MCP/2.1 package written for the JHCore MCP/2.1 implementation
for MOO.

You can find out more about MCP/2.1 here:

    http://www.awns.com/mcp/

The package dns-com-awns-ping allows both client and server to test
the latency of a user's connection, a rough indication of net-lag.
Accordingly the server can choose to 'back off' a bandwidth-heavy
activity to a slow user, to make the best of what little connectivity
the connection has to spare.

dns-com-awns-ping is symmetric, with both ends of the connection
supporting the following messages:

    #$#dns-com-awns-ping <authkey> id: <unique id>
    #$#dns-com-awns-ping-reply <authkey> id: <unique id>

In order to estimate the round-trip-time for a message the client
(or server) should first generate a unique id and make a note of
the current system time (Tping), then send the dns-com-awns-ping
message.  At the other end of the connection the recipient should
immediately reply with dns-com-awns-ping-reply substituting the
value of id.  Upon receipt of the dns-com-awns-ping-reply message
the client (or server) should make a note of the current system
time (Treply), and can then estimate the round-trip-time as:

    rtt = Treply - Tping

A different unique id should generated for each subsequent
dns-com-awns-ping message.

The MOO implementation contains the following useful API calls:

    package:ping(session)

	send the message dns-com-awns-ping to the client, recording
	the current time.  the package can estimate the round-trip-time
	which can be accessed via :avg and :slow

    package:avg(session)

	returns a float.  the average round-trip-time for the last
	5 dns-com-awns-ping messages.

    package:slow(session)

	returns 1 if the average round-trip-time is greater than
	1 second, else returns 0.


MANIFEST

    README			this file
    dns-com-awns-ping.moo	a MOO code @dump


INSTALL

As a non-wizard user port the MOO-code in the file dns-com-awns-ping.moo.
You'll need to load the file into a text editor and use search and
replace functions to replace the following strings with their
relevant values:

    __PACKAGE__		object id of generic MCP package
    __NEW__		object id of newly @create'd package
    __REGISTRY__	object id of $mcp.registry

To add the package to the MCP Registry, become a wizard and type:

    @add-package __NEW__ to __REGISTRY__

The package should be detected by your client the next time you
connect to the MOO.