A Survey on Handover Management in Mobility Architectures

This work presents a comprehensive and structured taxonomy of available techniques for managing the handover process in mobility architectures. Representative works from the existing literature have been divided into appropriate categories, based on their ability to support horizontal handovers, vertical handovers and multihoming. We describe approaches designed to work on the current Internet (i.e. IPv4-based networks), as well as those that have been devised for the "future" Internet (e.g. IPv6-based networks and extensions). Quantitative measures and qualitative indicators are also presented and used to evaluate and compare the examined approaches. This critical review provides some valuable guidelines and suggestions for designing and developing mobility architectures, including some practical expedients (e.g. those required in the current Internet environment), aimed to cope with the presence of NAT/firewalls and to provide support to legacy systems and several communication protocols working at the application layer

ALEX: Improving SIP Support in Systems with Multiple Network Addresses

The successful and increasingly adopted session initiation protocol (SIP) does not adequately support hosts with multiple network addresses, such as dual-stack (IPv4-IPv6) or IPv6 multi-homed devices. This paper presents the Address List Extension (ALEX) to SIP that adds effective support to systems with multiple addresses, such as dual-stack hosts or multi-homed IPv6 hosts. ALEX enables IPv6 transport to be used for SIP messages, as well as for communication sessions between SIP user agents (UAs), whenever possible and without compromising compatibility with ALEX-unaware UAs and SIP servers

IPv6 Network Mobility

Network Authentication, Authorization, and Accounting has been used since before the days of the Internet as we know it today. Authentication asks the question, “Who or what are you?” Authorization asks, “What are you allowed to do?” And fi nally, accounting wants to know, “What did you do?” These fundamental security building blocks are being used in expanded ways today. The fi rst part of this two-part series focused on the overall concepts of AAA, the elements involved in AAA communications, and highlevel approaches to achieving specifi c AAA goals. It was published in IPJ Volume 10, No. 1[0]. This second part of the series discusses the protocols involved, specifi c applications of AAA, and considerations for the future of AAA

Integrating Voice over IP Solution in IPv6 and IPv4 Networks to Increase Employee Productivity: A Case Study of Cameroon Telecommunications (Camtel), North-West

Telecommunications organizations have to follow the rapid innovation of technology if they want to face challenges raised by competition. The challenge to respond to the huge market demand of updated products and services from customers requires that the organization‘s working environment be equipped with tools and communication facilities that contribute to ameliorating productivity. Cameroon Telecommunications (Camtel) is facing a digital telephony and Internet Protocol strategic management challenge. Successful implementation cannot be achieved if the employees are still depending on the ageing public switched telephone network (PSTN) as their primary communication system, despite the frequent loss of dial tone experience in a day which can last up to a week, with serious repercussions on business activities and revenues. This study is designed to provide a solution to the telecommunications challenge. The fundamental question is how to integrate a digital telephony system that will provide telephony services in the existing IPv4 data network while prioritizing IPv6 traffic forwarding. This study proposes and implements solutions that integrate a Voice over IP solution with IPv6 as an alternative communication system that relies on the existing IPv4 data network. VoIP is deemed as one of the driving forces behind the adoption of IPv6. The purpose is to offer to workers an option that will free them from the poor Quality of Service (QoS) of their existing PSTN based solution, hopefully enhancing the overall productivity. This paper follows two research methodologies: Qualitative Research in Applied Situations and Engineering design process. The first part of this study reports the results of the evaluation of how much such a solution can enhance workers’ productivity. As it is important to provide an environment where IPv4 and IPv6 networks and applications/devices can interoperate in the context of VoIP; the second part describes practically a simulation environment where various configurations of network entities are done following a Dual-Stack transition approach. Document and records were used to gather information related to the structure, operations, and topological update of the Camtel’s existing IP data network. The findings demonstrated that VoIP can be an effective communication solution for Camtel and its implementation with IPv6 will be preferable. However, for this to be efficient there must be a provision of sufficient bandwidth and usage of types of equipment and transmission mediums that minimizes processing and propagation delays. Findings also reveal that better productivity will be achieved if workers are fully trained for the exploitation. This research article tries to highlight, discuss a required transition roadmap and extend the local knowledge and practice on IPv6. Future expansion of this research work will consist of deploying Dual-Stack VoIP in the remaining 9 regional offices for full integration in the corporate communication system of Camtel

On Identities in Modern Networks

Communicating parties inside computer networks use different kind of identifiers. Some of these identifiers are stable, e.g., logins used to access a specific service, some are only temporary, e.g., dynamically assigned IP addresses. This paper tackles several challenges of lawful interception that emerged in modern networks. The main contribution is the graph model that links identities learnt from various sources distributed in a network. The inferred identities result into an interception of more detailed data in conformance with the issued court order. The approach deals with network address translation, short-lived identifiers and simultaneous usage of different identities. The approach was evaluated to be viable during real network testing based on various means to learn identities of users connected to a network

Creation of value with open source software in the telecommunications field

Tese de doutoramento. Engenharia Electrotécnica e de Computadores. Faculdade de Engenharia. Universidade do Porto. 200

ACUTA Journal of Telecommunications in Higher Education

In This Issue President\u27s Message From the ACUTA CEO RIP for TDM IPTV: The Future of Gable TV Not All SIP Trunking ls Problem Free lnterview: Four Campuses Look at lPv6, SIB and More lPv6: What You Don\u27t Know CAN Hurt You Moving from the Old to the New 2013 Award Winners lnstitutional Excellence Award Honorable Mention: Abilene Christian University Virtual La

Taxonomy and analysis of IP micro-mobility protocols in single and simultaneous movements scenarios

The micro-mobility is an important aspect in mobile communications, where the applications are anywhere and used anytime. One of the problems of micro-mobility is the hand-off latency. In this paper, we analyse two solutions for IP micro-mobility by means of a general taxonomy. The first one is based on the Stream Control Transmission Protocol (SCTP), which allows the dynamic address configuration of an association. The second one is based on the Session Initiation Protocol (SIP), which is the most popular protocol for multimedia communications over IP networks. We show that for the SCTP solution, there is room for further optimisations of the hand-off latency by adding slight changes to the protocol. However, as full end-to-end solution, SCTP is not able to handle simultaneous movement of hosts, whose probability in general cannot be neglected. On the other hand, the SIP can handle both single and simultaneous movements cases, although the hand-off latency can increase with respect to the SCTP solution. We show that for a correct and fast hand-off, the SIP server should be statefull