Controller placement optimization for Software Defined Wide Area Networks (SDWAN)

Software Defined Networking (SDN) has emerged as a promising solution to revolutionize network deployment, operations and economic growth. This paradigm aims to address management and configuration complexities in legacy networks so as to reduce the total cost associated with deploying and running telecommunication infrastructures. At the heart of SDN is a controller which oversees orchestration of resources. An important problem that must be addressed during the initial design of an SDN-based network deployment is to find the optimal number of controllers and their locations, to achieve desired operational efficiency. This problem constitutes competing objectives such as latency, load balancing, and reliability. We apply Silhouette Analysis, Gap Statistics and the Partition Around Medoids (PAM) algorithms and, unlike previous work, we add a new method for solving the controller placement problem using an emulation orchestration platform. Our approach aims to optimize controller-to-node latency, alleviate control-plane signalling overhead and ensure control-plane resiliency. Our results for South African national research network (SANReN) reveal that deploying two controllers yields the lowest latency, reduces control-plane signalling overhead and guarantees control-plane resiliency. Our approach can be used by network operators as a guideline to start integrating SDN or plan a new SDN deployment, by helping them make quick automatic decisions regarding optimal controller placement.

A TOTP-Based Enhanced Route Optimization Procedure for Mobile IPv6 to Reduce Handover Delay and Signalling Overhead

Due to the proliferation of handheld mobile devices, multimedia applications like Voice over IP (VoIP), video conferencing, network music, and online gaming are gaining popularity in recent years. These applications are well known to be delay sensitive and resource demanding. The mobility of mobile devices, running these applications, across different networks causes delay and service disruption. Mobile IPv6 was proposed to provide mobility support to IPv6-based mobile nodes for continuous communication when they roam across different networks. However, the Route Optimization procedure in Mobile IPv6 involves the verification of mobile node’s reachability at the home address and at the care-of address (home test and care-of test) that results in higher handover delays and signalling overhead. This paper presents an enhanced procedure, time-based one-time password Route Optimization (TOTP-RO), for Mobile IPv6 Route Optimization that uses the concepts of shared secret Token, time based one-time password (TOTP) along with verification of the mobile node via direct communication and maintaining the status of correspondent node’s compatibility. The TOTP-RO was implemented in network simulator (NS-2) and an analytical analysis was also made. Analysis showed that TOTP-RO has lower handover delays, packet loss, and signalling overhead with an increased level of security as compared to the standard Mobile IPv6’s Return-Routability-based Route Optimization (RR-RO).