Due to the increasing demand of secure communications over the Internet, IPsec
gateway becomes one of the popular methods to provide security services to all clients in
a protected subnet. The processing speed of an IPsec gateway is critical to the overall
network throughput. To accelerate processing speed and improve reliability, cluster
technology was inherently applied to the design of a modern IPsec gateway. Traditional
dispatcher/master-based cluster technique must have a centralized dispatcher to handle all
incoming and outgoing messages. The failure of single point, that is the dispatcher, will
cause the crash of the entire gateway. The dispatcher will also become the bottleneck if
its computation power cannot handle all messages. With the proposed clustered
architecture, the speed of IPsec gateway increases drastically and almost linearly. As
the experiment results showed, the proposed clustered architecture provides better
performance and can scale up easily.
