The Real-time Transport Protocol (RTP ) has become a widely implemented internet-standard protocol for transport of real-time data. It provides a mechanism for the participants to give feedback about the service using the RTP Control Protocol (RTCP ). This document aims to presents the platform independent RTP implementation in Java. This implementation, which is available as a java.net.RTP package, can be easily incorporated into an application, which then has access to all of the transport level features RTP and RTCP provide. This package also provides out of band initialization classes, which implement a late-initialization protocol. These classes could be used to implement a late initialization server which is capable of synchronizing late-joining clients.