Reliable Data Protocol(RDP) is a reliable connection-oriented transport protocol in which the data is packetized, the transmission of which can be in ordered and unordered sequence. It forms a complement to the unreliable services of the IP protocol.
With the RDP protocol, data is transmitted in successive chunks or RDP segments that are identical in size for both sender and receiver. The prerequisite is that the applications can process the packetized data. The reliability of the Reliable Data Protocol is based on the detection of unacknowledged data packets that are sent back. For this purpose, a positive acknowledgement( ACK) procedure is implemented in the Reliable Data Protocol(RDP).
The Reliable Data Protocol is specified by the Internet Engineering Task Force( IETF) and is described under RFC 908 and 1151. It differs from the Transmission Control Protocol( TCP) in that it is a packet-based datagram service and has a simple structure and semantics.