A multi-party reliable transport protocol for use by a higher layer application. A single session source distributes database updates to multiple receivers via a distribution tree. A node desiring to join a session selects a directly-connected node on a path upstream to a source by accessing unicast routing protocol information and sends a "Join" message to this upstream neighbor. Each node participating in the scheme handles retransmission requests from its directly-connected downstream neighbors. A supported application provides storage of previously transmitted information for potential retransmission.