Protocol Stack Architecture

We have developed architectural enhancements for Unix-based servers to provide these mechanisms. Figure 4 shows the basic components of the enhanced protocol stack architecture, with the new capabilities utilized either by user-space agents or applications themselves. This architecture permits control over an application's inbound network traffic via policy-based traffic management [10]; an adaptation/policy agent installs policies into the kernel via a special API. The policy agent interacts with the kernel via an enhanced socket interface by sending (receiving) messages to (from) special control sockets. The policies specify filters to select the traffic to be controlled, and actions to perform on the selected traffic. The figure shows the flow of an incoming request through the various control mechanisms.

4: Enhanced protocol stack architecture.