Method and apparatus for the testing and evaluation of geographically distributed telecommunication networks.

摘要

The dynamic functional behavior of geographically distributed fast packet switching systems, including those which accommodate high-priority circuit switched traffic and low-priority packet switched traffic, can be tested in real-time by sending test packets from one or more source nodes through the system to specific destinations that comprise a test packet analyzer. The test packets have the same structure as the data packets but in their payload portion carry the entire information required to perform the testing. The nature of that test information depends on the characteristics of a set of predefined system errors the verification system is supposed to identify. For example, for detecting a specific set of errors encompassing packet loss, packet duplication, wrong packet sequence, packet at wrong output, packet corruption, packet length error, and unacceptable packet delay, the test information would include an input address indicating the source of the test packet, a sequence number defining the order in which the packet should arrive at the destination, time bits relating to the packet length and/or to the expected packet transmission delay, and a cyclic redundancy code which covers the entire contents of the test packet, including its control portion. Each analyzer at a receiving station operates autonomously from the senders and processes all received traffic in real-time: this enables it to recognize all defined system errors, even those occurring with very low probability, at the packet level. <IMAGE>