Chasing errors through the network stack: A testbed for investigating errors in real traffic on optical networks

A testbed is described that allows both physical layer errors to be observed and analyzed, as well as monitoring network performance via frame loss. Real network traffic loads can be used for testing so that all measurements taken are representative of what would be seen in a deployed system. We illustrate our testbed with an examination of the behavior of a well-known networking standard, Gigabit Ethernet, in conditions of reduced receiver power on optical fiber. Our testbed results show that the line codes used to represent the data in the network affect the bit error rate for that data. Along with the previously reported result that bit error rate and packet error rate have only a weakly deterministic relationship, this highlights the need for testing of all network layers within a complete system carrying real-world traffic.