In order to support more information in the form of video, audio, data, and telephony at higher rates, high performance systems are required. Data products, for instance, are increasingly being used to carry traffic that is delay-sensitive. For example, to play a video or to start a real-time voice conversation, it is critical to manage and control packet latency as well as jitter in order to have video and/or voice packets delivered properly. High performance systems often mean low system (or packet) latency and/or jitter. Latency typically indicates a delay for a packet to travel through a system and jitter means the change in latency from packet to packet.
Although networks are typically designed to absorb some jitters by data buffering as well as jitter compensating algorithms, excessive jitters and latencies can cause buffer to overflow and underflows. System (or packet) latency and/or jitter are typically important information to assess and identify the real performance of a network. It should be noted that while too much latency can often render interactive applications such as voice and video unusable, too much jitter renders the service unusable. A problem associated with system latency and jitter is that they are difficult to measure and detect.
A conventional approach of measuring and/or monitoring latency and jitter is to use a third party (or vendor) test equipment. The third party test equipment is typically attached to the input port(s) and output ports of a network system such as a router to detect and record delays for each packet traveling through the network system. From recorded delays, the third party test equipment can provide latency and jitter associated with each packet or packets.
Using third party test equipment, however, is often difficult to measure real-time delays (in turn measuring latency and jitter) in the filed. Measuring latency and/or jitter using third party test equipment is commonly carried out in a controlled laboratory environment.