Peer-to-peer name resolution for handsets An investigation and an implemented solution

Abstract

To increase availability of the Voice over IP (VoIP) service, used by handsets in a network, it is desirable to find alternative ways of communication when the network is down. An alternative solution could be to send information directly between handsets, without the use of an intermediate server. The report examines a few examples of di erent Peerto- Peer (P2P) solutions with an emphasis on name resolution for the Session Initiation Protocol (SIP). One example shows how this could be carried out and what to expect with this communication strategy. The report has been written in collaboration with the Ascom company, a company that is a vendor of mission-critical handsets and the work has been carried out with their standards of communication in mind. There is limited data space and processing power in the handsets which are also taken into account. The result of the implemented solution implies that in some cases, a P2P solution could be interesting, because it would be possible to contact the callee directly without using an intermediate server, which means less traffic load and less complexity saving battery power for the handsets. The report tries to meet these requirements and the results were interesting for the company.