Low Cost Grating Based Laser Sensor

Not Available A key problem with the Internet is the slowness with which the underlying IP protocol can evolve. Though this protocol is very successful, there are many things for which it is not well suited, and a variety of efforts have been initiated to revise the standard to address these shortcomings. About four years ago the Defense Advanced Projects Agency (DARPA) launched an ambitious program to develop a technology, known generally as Active Networking (AN), intended to address this problem of slow deployment. An active network is one in which the routers can be customized to run communication- oriented protocols on a per-user, per-flow, or even per-packet basis. In particular, users are allowed to deploy or invoke programs within the network rather than just at endpoints. This allows a range of new protocols to be deployed quickly within the network by programming them using a more high-level interface. The goal of this proposal is to take steps to commercialize one of the most successful and widely-used active network technologies, and take a first step toward developing applications based on that technology through an experiment on the ABONE. The basic technology is that of PLAN, the Packet Language for Active Networks, designed by the SwitchWare Project at the University of Pennsylvania. The application is endpoint emulation, a service in which an active router serves as a proxy for a destination that becomes temporarily inaccessible. Such a service would allow certain kinds of communication between two endpoints even if they were never connected to one another at the same time due to erratic network connectivity or the unavailability of the endpoints themselves. The resulting service is much more general than an answering-machine since it does not require designation of specific proxy to hold the message.