A measurement analysis of Internet traffic over frame relay

Various approaches have been proposed and implemented to relieve the congestion in the Public Switched Telephone Networks (PSTNs) induced by recent meteoric growth of Internet services. The Internet/Intranet Transport Service (IITS) offered by the Southwestern Bell Telephone (SWBT) Company provides an example of one such implementation which off-loads the long-holding time data traffic from PSTNs to a packet technology (in this case Frame Relay).This paper describes analysis of 1997 IITS traffic jointly performed by SWBT and Bellcore with the goal of gaining insights into the nature of the Internet traffic over the Frame Relay technology, and deriving practical traffic engineering guidelines for efficiently managing the network elements to provide Quality-of-Service (QoS) to customers. The analysis was carried out at the frame level as well as the call level. The results demonstrate that traffic (both frame and byte count processes) at the frame level is self-similar with long-range dependent characteristics, while call arrivals are inhomogeneous Poisson processes and call holding times have heavy tails. Frame size statistics are explored, revealing a packet fragmentation issue that can unnecessarily decrease resource efficiency. The impacts of load balancing schemes (implemented by the equipment suppliers) on the traffic characteristics is also observed.