Information Channels
At the base of the middleware is a framework initially developed for use in the prior NGI project. The InformationChannels framework supports the formation of complex networks of communicating application components (clients and servers) with minimal direct user intervention. The framework accomplishes this by focusing on the channels of information exchanged between application components.
Applications announce their ability to provide or consume channels of information by periodically sending channel announcements on a multicast address. A channel is identified by the provider's name, the channel's name and the channel's type. Channel announcement specify the time interval used for resending the announcement. The announcement contains the network parameters (ip addr, port number etc) required to establish the connection.
A registration server (possibly multiple instances for redundancy) listens to the multicast address and maintains a list of all active channels. The registration server responds to queries about currently active channels. Application components can use this capability to discover the availability of remote services. A web based query page also allows users to discover the existence of channels.