Sun Baolin was bom in Hubei in 1963. He is currently an associate professor and Ph. D. candidate in computer science of the Wuhan University of Technology. His research interests include QoS multicast routing, distributed computing and protocol engineering. E-mail: sun0163@163.com. Li Layuan was bom in 1946. He received the BE degree in Communication Engineering from Harbin Institute of Military Engineering, in 1970 and the ME degree in Communication and Electrical Systems from Huazhong University of Science and Technology, in 1982. He is currently a Professor and Ph. D. Supervisor in Computer Science, and Editor in Chief of the Journal of WUT. His research interests include high-speed computer networks, protocol engineering and image processing.