Topology overlays for dedicated protection Ethernet LAN services in advanced SONET/SDH networks

The explosion of information technology (IT) services coupled with much-increased personal and scientific computing capabilities has resulted in great demand for more scalable and reliable networking services. Along these lines, carriers have spent large sums to transition their legacy\u27 SONET/SDH voice-based networking infrastructures to better support client-side Ethernet data interfaces, i.e., next-generation SONET/SDH (NGS). In particular, a key addition here has been the new virtual concatenation (VCAT) feature which supports inverse multiplexing to \u27split\u27 larger connection requests in to a series of independently-routed \u27sub-connections\u27. As these improved infrastructures have been deployed, the design of new Ethernet over SONET/SDH (EoS) services has become a key focus area for carriers, i.e., including point-to-point and multi-point services. In light of the above, this thesis focuses on the study of improved multi-point EoS schemes in NGS networks, i.e., to provision robust \u27virtual LAN\u27 capabilities over metro and wide-area domains. Indeed, as services demands grow, survivability considerations are becoming a key concern. Along these lines, the proposed solution develops novel multi-tiered (partial) protection strategies. Specifically, graph-theoretic algorithms are first proposed to interconnect multi-point node groups using bus and minimum spanning tree (MST) overlays. Next, advanced multi-path routing schemes are used to provision and protect these individual overlay connections using the inverse-multiplexing capabilities of NGS. Finally, post-fault restoration features are also added to handle expanded failure conditions, e.g., multiple failures. The performances of the proposed multi-point EoS algorithms developed in this research are gauged using advanced software-based simulation in the OPNET ModelerTM environment. The findings indicate that both the bus and MST overlays give very good performance in terms of request blocking and carried load. However, the MST-based overlays slightly outperform the bus-based overlays as they allow more efficient topology designs. In addition, the incorporation of dynamic load state information in the selection of bus and/or MST overlays is also very beneficial as opposed to just using static hop count state. Furthermore, inverse-multiplexing is highly-effective, yielding notably higher carried loads when coupled with load-balancing sub-connection routing. Finally, results also show that post-fault restoration is also a very effective means of boosting EoS LAN throughputs for partially-protected demands, consistently matching the reliability of full-protection setups.\u2

Multistage Switching Architectures for Software Routers

Software routers based on personal computer (PC) architectures are becoming an important alternative to proprietary and expensive network devices. However, software routers suffer from many limitations of the PC architecture, including, among others, limited bus and central processing unit (CPU) bandwidth, high memory access latency, limited scalability in terms of number of network interface cards, and lack of resilience mechanisms. Multistage PC-based architectures can be an interesting alternative since they permit us to i) increase the performance of single software routers, ii) scale router size, iii) distribute packet manipulation and control functionality, iv) recover from single-component failures, and v) incrementally upgrade router performance. We propose a specific multistage architecture, exploiting PC-based routers as switching elements, to build a high-speed, largesize,scalable, and reliable software router. A small-scale prototype of the multistage router is currently up and running in our labs, and performance evaluation is under wa

Network Route Minimization Using Time Based Interface Control

The demand for networking is increasing day by day with the progressive need of communication. As a result the communication channel and state database are increased with correspondingly. A rise in the amount of state database maintenance is one of the important cost effective issues for communication devices. The most challenging think is router state database reducing. As of now, many different types of state table accomplishments method are proposed for router state database reducing. In this purpose, we apply and modify the SPF algorithm by time based interface control. Dijkstra’s SPF algorithms searching the shortest specific link among from the all link then build a router state database table. If the state table size is little amount, then router OS using little amount of clock cycle. Some of Network interface are down for a fixed amount of time in a router. Therefore, we proposed a time based interface control method on SPF algorithm for re-build a new state database table. The modified SPF time based interfaces control algorithm suggests a new approach on dynamic routing protocol for reducing routing table size and saving router state-database size, resulting in a better convergence time

QoS-based routing over software defined networks

Quality of Service (QoS) relies on the shaping of preferential delivery services for applications in favour of ensuring sufficient bandwidth, controlling latency and reducing packet loss. QoS can be achieved by prioritizing important broadband data traffic over the less important one. Thus, depending on the users’ needs, video, voice or data traffic take different priority based on the prevalent importance within a particular context. This prioritization might require changes in the configuration of each network entity which can be difficult in traditional network architecture. To this extent, this paper investigates the use of a QoS-based routing scheme over a Software-Defined Network (SDN). A real SDN test-bed is constructed using Raspberry Pi computers as virtual SDN switches managed by a centralized controller. It is shown that a QoS-based routing approach over SDN generates enormous control possibilities and enables automation