Recommendation ITU-T Q.4101 specifies procedures for construction and recovery of a hybrid overlay network. The hybrid overlay network constructs data broadcast tree among peers, and calibrate the topology of the overlay network whenever peers are joining and leaving. On calibrating the hybrid overlay network, it needs to be stable even during the reconstruction process. In order to doing this, this Recommendation specifies the procedures for construction and recovery of the tree-based hybrid overlay network, and also specifies the procedures for recovering data that may been lost during the tree recovery procedures.