MUSeS: Mobile User Secured Session

International audienceMobility and security are very important services for both current and future network infrastructures. However, the integration of mobility in traditional virtual private networks is difficult due to the costs of re-establishing broken secure tunnels and restarting broken application connections. In order to address this issue, we propose a new communication system called Mobile User Secured Session. Based upon a peer-to-peer overlay network, it provides security services to the application layer connections of mobile users. The secure and resilient sessions allow user connections to survive network failures as opposed to regular transport layer secured connections. We have implemented a prototype and have assessed its proper functioning by running experimentations upon a simple virtual dynamic network

Mobile Communication with Virtual Network Address Translation

Virtual Network Address Translation (VNAT) is a novel architecture that allows transparent migration of end-to-end live network connections associated with various computation units. Such computation units can be either a single process, or a group of processes of an application, or an entire host. VNAT virtualizes network connections perceived by transport protocols so that identification of network connections is decoupled from stationary hosts. Such virtual connections are then remapped into physical connections to be carried on the physical network using network address translation. VNAT requires no modification to existing applications, operating systems, or protocol stacks. Furthermore, it is fully compatible with the existing communication infrastructure; virtual and normal connections can coexist without interfering each other. VNAT functions entirely within end systems and requires no third party proxies. We have implemented a VNAT prototype with the Linux 2.4 kernel and demonstrated its functionality on a wide range of popular real-world network applications. Our performance results show that VNAT has essentially no overhead except when connections are migrated, in which case the overhead of our Linux prototype is less than 7 percent

Robust TCP Connections for Fault Tolerant Computing

When processes on two different machines communicate, they most often do so using the TCP protocol. While TCP is appropriate for a wide range of applications, it has shortcomings in other application areas. One of these areas is fault tolerant distributed computing. For some of those applications, TCP does not address link failures adequately: TCP breaks the connection if connectivity is lost for some duration (typically minutes). This is sometimes undesirable. The paper proposes robust TCP connections, a solution to the problem of broken TCP connections. The paper presents a session layer protocol on top of TCP that ensures reconnection, and provides exactly-once delivery for all transmitted data. A prototype has been implemented as a Java library. The prototype has less than 10% overhead on TCP sockets with respect to the most important performance figures

A session-based architecture for Internet mobility

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, February 2003.Includes bibliographical references (p. 179-189).The proliferation of mobile computing devices and wireless networking products over the past decade has led to an increasingly nomadic computing lifestyle. A computer is no longer an immobile, gargantuan machine that remains in one place for the lifetime of its operation. Today's personal computing devices are portable, and Internet access is becoming ubiquitous. A well-traveled laptop user might use half a dozen different networks throughout the course of a day: a cable modem from home, wide-area wireless on the commute, wired Ethernet at the office, a Bluetooth network in the car, and a wireless, local-area network at the airport or the neighborhood coffee shop. Mobile hosts are prone to frequent, unexpected disconnections that vary greatly in duration. Despite the prevalence of these multi-homed mobile devices, today's operating systems on both mobile hosts and fixed Internet servers lack fine-grained support for network applications on intermittently connected hosts. We argue that network communication is well-modeled by a session abstraction, and present Migrate, an architecture based on system support for a flexible session primitive. Migrate works with application-selected naming services to enable seamless, mobile "suspend/resume" operation of legacy applications and provide enhanced functionality for mobile-aware, session-based network applications, enabling adaptive operation of mobile clients and allowing Internet servers to support large numbers of intermittently connected sessions. We describe our UNIX-based implementation of Migrate and show that sessions are a flexible, robust, and efficient way to manage mobile end points, even for legacy applications.(cont.) In addition, we demonstrate two popular Internet servers that have been extended to leverage our novel notion of session continuations to enable support for large numbers of suspended clients with only minimal resource impact. Experimental results show that Migrate introduces only minor throughput degradation (less than 2% for moderate block sizes) when used over popular access link technologies, gracefully detects and suspends disconnected sessions, rapidly resumes from suspension, and integrates well with existing applications.by Mark Alexander Connell Snoeren.Ph.D