PERFORMANCE-MEASUREMENTS AND TRAFFIC CHARACTERIZATION ON THE ATM PILOT NETWORK

From mid-94 to end-95 the ''Performance Working Group (PWG)'' of the A TM PILOT has carried out a lot of measurements (in relationship to fun ctions available on test equipments). The results obtained were mainly related to ATM layer performance measurements (availability and non t ime-related performance parameters) and to traffic characterization. P erformance measurements aimed at checking the validity of the set of p roposed or standardized ATM layer performance parameters, at studying the sensitivity of the parameters definitions and at obtaining early r esults in order to propose performance objectives for the relevant rec ommendations. These results have shown that the ATM layer performance is very much dependent of the observation period of time and of the ph ysical path of the connection under test. Furthermore it has been obse rved that the ATM layer performance is not so sensitive to the paramet er definitions and the associated thresholds. Traffic characterisation is necessary to identify what is going on in the network (will the ce lls be equally spaced or will they come in bursts ?). The PWG had take n the opportunity to do field trials with real traffic coming from Pil ot and has carried out a range of tests on both CBR sources (carrying voice or video applications) and VER sources (multimedia application o r LAN to LAN interconnection). Two main traffic types have been observ ed during the tests: CBR sources carrying voice or video applications. VBR sources with multimedia applications or LAN to LAN interconnectio n using the SMDS/-CBDS service.