Architecture

SmartSockets Multicast is designed to be connection-less and efficient. The routers in a network assist the end-host nodes by selectively forwarding protocol information along the most efficient path. However, a PGM-capable router is not mandatory for a small number of receivers, less than 100.

In addition, TIBCO has developed a product to act as a PGM-capable Network Element (NE) for networks without PGM-capable routers in them. PGM is a negative acknowledgment (NAK)-based protocol where the receivers notify the sender only in the case of message loss, the beneficial side-effect being the preservation of bandwidth.

A PGM sender does not explicitly know the receivers of any particular piece of data—yet this is not a liability. In fact, with its loose group membership model, PGM is extremely well-suited for applications that need to leave and join multicast groups quickly and with a minimum of control messages (or none at all). This makes PGM an ideal choice for applications that have transient or mobile properties.