US Patent 7123616 Determining round-trip time delay

A method of and an apparatus for determining real-time data latency are disclosed. The method may include creating a plurality of outgoing data packets having an outgoing time stamp and a group identifier. The outgoing data packets may be transmitted onto a network. A plurality of incoming data packets may be received over the network. For each of the incoming data packets, a round-trip time delay for the incoming data packet may be calculated. Statistics for the incoming data packets may be updated based on the round-trip time delay and the group identifier included in the incoming data packet. The method may be implemented on an apparatus.