1. Distributed Systems Technology Center (DSTC), Monash University Caulfield Campus, 900 Dandenong Road, Caulfield East, VIC 3145, Australia
2. Max-Planck-Institut für Informatik, Stuhlsatzenhausweg 85, D-66123 Saarbrücken, Germany
3. C&C; Research Laboratories, NEC Europe, Rathausallee 10, D-53757 Sankt Augustin, Germany