WIRELESS INTERNET TELEPHONY

INTRODUCTION

Internet Telephony can be defined as real time voice or mult-imedia communication over the internet or more generally over packet switched network. two telecommunication standardizations bodies are now used IP (session initiation protocol ) as basis to make wireless Internet telephony a reality in the context of third generation wireless telecom- munication network.Millions of highly mobile end-user who are frequently change their location will access Internet telephony services using wide range of wireless devices . Advances service anything that goes beyond two party call . It may or may not be related telephony like call diversion , call transfer, blend telephony etc.In wireless telephony end-user need to have to access these services from any terminal or from anywhere .this requirementis called universal access.

This paper presents the design ,the implementation , & the evaluation of an advanced service architecture for wireless Internet telephony.
The architecture relies on mobile agent that act as folder & carries services . Carrying services mobile agent raises the issue of agent upgrading when end-user subscribes or unsubscribes to service .mobile agent is software program whose main characteristics is ability to move from node to node on network during execution . The mobile agent provide universal access requirement with an efficient manner . They can relocate to new devices being used by end-user or the SIP proxy H.323 gatway that is close to the end-user. A mobile agent that we call MSA (mobile service agent) &there are also some important elements like Service Creation Unit , Service Management Unit & S - ervice Publication Unit .The SCU handles the creation of new services . The SMU manages user subscription creates and maintains MSAs. The service publication unit is the interface of the system to the external world and can be simple web server . our architecture tackles the issue by proposing and eval -uating two novel schemes :agent swapping and on-the fly updating . Althogh wireless Internet Telephony is our prime targrt ,the architecture is ,to a large extent ,independent of the lyiny network and therefore applicable to Internet telephony in general.