World Wide Conferencing Network
WWCN is a system that provides multimedia conferencing services on a world-wide scale. It has been optimized for realtime data delivery: music, voice, video, pictures, text, software updates, and so on. To cope with today's bandwidth scarcity, it implements a reliable "multicasting" technology (one to many data communication) over standard TCP (internet) connections.
WHAT IS WWCN?
Introduction
White papers
HOWTO...
connect
tune in
build a network?
SOFTWARE
multimedia players
multimedia producers
chat clients
server software
How to build a WWCN network?
This page will concentrate on the 'datasphere' package, because that's the only package currently available supporting the WWCN protocol. You can download it from this site.A WWCN network has three types of servers:
- a conferencing server, that maintans channels and transports the data transmitted on those channels;
- a channel directory server, that maintains the authoritative list of channels and facilitates the conferencing servers to keep consistent lists of channels;
- a user directory server, that maintains the authoritative list of users and facilitates the conferencing servers to keep track of users.
WWCN clients only connect to conferencing servers, and do not need to connect to any of the other two types of server. The conferencing servers are connected in a mesh (the CS network); see the picture below.
The conferencing servers each connect to one or more channel directory servers, and to one or more user directory servers. And, to make things more complex, the channel directory servers are also connected in a mesh themselves (the CDS network). You might have expected that the user directory servers are also connected in a mesh (the UDS network)... see the picture below.
Each server in WWCN has a unique identifier. This is crucial; if you build a network with two servers having the same ID, then the routing algorithms will fail miserably. For two servers to connect together, two passwords are needed: a 'from' and a 'to' password. A server 'A' sends it 'to' password for the other end 'B' to verify: it has to match the 'from' password in B's configuration file.
In the Datasphere package, each type of server has a list of 'peer connects'. For a conferencing server, this is the list of 'fellow conferencing servers' it connects to. For a channel directory server, it is the list of 'fellow channel directory servers' it connects to. Same goes for user directory servers. Such a list has the following format:
# HOSTNAME PORT RATE ID PASSWORD FROM/TO AUTOCON MIN
peer_connects = {
server.domain.org 7777 100000 1 secret terces yes 5
another.server.com 7777 50000 3 ykoops spooky no
}
The 'RATE' field is the maximum amount of bytes per second that the
server will accept data at. Data sent at a higher rate will cause network
buffers to overflow, after which most OS'es terminate the connection.
This RATE parameter is to allow network operators to have some control
over the amount of traffic a server draws.
The 'ID' field is the identifier that belongs to the hostname; the 'AUTOCON' field indicates whether or not a connection should be made automatically. Valid values are 'yes' or 'no'. If the field is 'yes', then also a field is required that indicates how often the server should try to make a connection (in minutes). Note that the name 'peer' here does not mean that WWCN is a peer-to-peer network. It is not, at least not in the 'gnutella' sense.
A conferencing server has a similar list to specify the list of channel directory servers it should connect to ('cds_connects') and a list of user directory servers it should connect to ('uds_connects').
This information should be enough to get you going! If you have questions, don't hesitate to mail grit@wwcn.org.