Applying Different Types of Mobility in One Network

Abstract

The importance of mobility nowadays is growing exponentially and who knows what we can expect in future from all the new wireless technologies? Thus there is an inexorable increase in need for mobile networking that is aimed to support the requirements of today s new class of Internet users as they roam about with sophisticated laptop computers and digital wireless data communication devices. As the number of advanced network services increases and they become more and more available, every network device will take advantage of mobile networking technology to offer maximum flexibility to the customers needing those devices. Actually, it is only imagination, what is setting limitations on what we can expect in future. Mobile networking technology comprises different mobility aspects, which are described in this thesis. All of these aspects have already been thoroughly studied and possible solutions, supporting each particular type, have been proposed. However, it is unknown how all these solutions will behave when implemented together on one network. We shall through our thesis study this problem on a particular case of terminal mobility and personal mobility, where the first one is supported by Mobile IP and the latter one is supported by SIP. Mobile IP is an IETF protocol that handles the terminal mobility at the network layer, leaving transport and other higher layers unaffected, so that none of the existing routing mechanisms, hosts and applications need to be modified. In our thesis we give an overview of this protocol, paying special attention to the details that are of vital importance for providing terminal mobility along with the other types of mobility. The Session Initiation Protocol is an IETF protocol for establishing, modifying and termination multimedia sessions on IP-based network. In our thesis we give an introduction to SIP, and especially focus on its capabilities, which are used for providing personal mobility. After that we provide four approaches for how these two protocols may interact when being implemented on the same network. For each approach we provide an overview of its functionality and a detailed description of message flow and how these messages are processed by units. All the required additional functionality is highlighted along with the advantages and disadvantages of each approach, provided in the analysis-section. Last we provide an evaluation of the approaches where we compare them in order to be able to find out what solution is suited best for being implemented in practice as a solution for the problem.