Russell J. Clark

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BGP severely constrains how networks can deliver traffic over the Internet. Today's networks can only forward traffic based on the destination IP prefix, by selecting among routes offered by their immediate neighbors. We believe Software Defined Networking (SDN) could revolutionize wide-area traffic delivery, by offering direct control over(More)
Enterprise network security is typically reactive, and it relies heavily on host security and middleboxes. This approach creates complicated interactions between protocols and systems that can cause incorrect behavior and slow response to attacks. We argue that imbuing the network layer with mechanisms for dynamic access control can remedy these ills. We(More)
Network conditions are dynamic; unfortunately, current approaches to configuring networks are not. Network operators need tools to express how a network’s data-plane behavior should respond to a wide range of events and changing conditions, ranging from unexpected failures to shifting traffic patterns to planned maintenance. Yet, to update the network(More)
We describe a reactive robotic control system which incorporates aspects of machine learning to improve the system's ability to successfully navigate in unfamiliar environments. This system overcomes limitations of completely reactive systems by exercising on-line performance enhancement without the need for high level planning. The results of extensive(More)
In this paper, we present an entry for the 2011 MobileHCI design competition. Our aim is to define the "essence" of mobile communication and connectivity, and illustrate it via a design example called Spaces Without Faces, an application to locate quiet study spaces on a university campus. We argue that the essence of mobile communication and connectivity,(More)
This article presents a new line of research investigating on-line learning mechanisms for autonomous intelligent agents. We discuss a case-based method for dynamic selection and modi cation of behavior assemblages for a navigational system. The casebased reasoning module is designed as an addition to a traditional reactive control system, and provides more(More)
We present a new line of research investigating on-line adaptive reactive control mechanisms for autonomous intelligent agents. We discuss a case-based method for dynamic selection and modification of behavior assemblages for a navigational system. The case-based reasoning module is designed as an addition to a traditional reactive control system, and(More)
The Dynamic Host Configuration Protocol (DHCP) is used to dynamically allocate address space to hosts on a local area network. Despite its widespread usage, few studies exist on DHCP usage patterns, and even less is known about the importance of setting the lease time (the time that a client retains ownership over some IP address) to an appropriate value.(More)
The IP Multimedia Subsystem (IMS) is the basis for a significant new architecture for mobile applications incorporating voice, video and data services. The IMS is an overlay network on top of IP that uses SIP as the primary signaling mechanism. The IMS presents several new security challenges for both network providers and network users. This paper provides(More)