Acknowledgements This research was funded by IWT.

1. Protocol stacksin controlSam MichielsDept. of Computer Science G B S schedulerstrategy Problem context Research relevance • Protocol stack problems & characteristics • Poor separation of concerns • Poor customizability • Poor reusability • Unpredictable load conditions • Protocol stack development productivity must increase • Growing demand for application-specific customizations • Customizable protocol stacks require powerful software design concepts DiPS+ Strategy RADIUS authentication RADIUS accounting Distrinet Protocol Stack component framework AcctReqAuthchecker Accounter Authenticator NASchecker Accept replypreparator Acct replypreparator NASchecker DC Reject replypreparator Attributeparser Attributeconstructor Functional/concurrency/dispatching components Concurrencycomponent Headerparser Attributeconstructor Software architecture(pipe & filter, blackboard, layered) Separate data & management plane Attributeparser Headerconstructor Headerconstructor Headerparser Concurrencycomponent Self-healing system behavior(e.g. load management) UDP/IP protocol stack Research results Authentication requests Gold users Authentication requests In = 30 r/sOut = 20 r/s In = 30 r/sOut = 30 r/s Silver users I III II Bronze users I III II I III II Accounting requests Accounting requests In = 300 r/sOut = 200 r/s In = 200 r/sOut = 200 r/s In = 30 r/s In = 30 r/s In = 30 r/s In = 60 r/s In = 60 r/s In = 30 r/s In = 30 r/s In = 30 r/s DiPS+ server protects itself against overload (self-healing) Non DiPS+ RADIUS randomly drops packets In = 30 r/s Acknowledgements This research was funded by IWT. Further information Sam Michiels K.U.Leuven – Dept. ComputerwetenschappenDistriNet Research Group Celestijnenlaan 200A 3001 Leuven (Heverlee), Belgium sam.michiels@cs.kuleuven.ac.be Supervisors: Pierre Verbaeten Wouter Joosen Tel.: +32 16 32 70 68 Fax: +32 16 32 79 96 www.cs.kuleuven.ac.be