DAN: distributed code caching for active networks

Active networking allows the network infrastructure to be programmable. Previous research focused on two commonly separated approaches: "capsules" and "programmable switches". Capsules are typically small programs in packets which flow through the network and are executed in-band on nodes receiving them. Programmable switches are network devices which offer a back-door to inject code by a network administrator out-of-band in order to enhance the device's capabilities. By combining these two approaches, this paper proposes a novel system architecture which allows both application specific data processing in network nodes as well as rapid deployment of new network protocol implementations. Instead of carrying code, data packets carry pointers to digitally signed active modules initially loaded on-the-fly, inband from trusted code servers on the network. Packet processing runs at high speed, may access and modify the whole network subsystem and no potentially slow virtual machines are needed.