Voice Over Ip Phones To Enhance Call Quality

With the development of technology of VoIP, IP telephone has had great influenceupon traditional communication.VoIP network devices include gateway,gatekeeperand so on. If IP telephone wants to compete with traditional telephone, it mustimprove its voice quality. If IP telephone could successfully solve the problem ofvoice quality, it will have great market space.Compared with traditional telephone, IP telephone has many advantages, such ashigher efficience in using the network, lower cost, more additional function and so on.Until now, IP telephone technology has acquired great progress in perfecting andameliorating its functions. IP network telephone include two protocols:H323 protocolput forward by ITU-T and the IP telephone techonology based on SIP put forward byIETF. And now H323 protocol has become the maturest and the most widely usedstandard protocol.This paper introduced the development of IP telephone, the basic theory of IP telephone, and the system structure of H.323 protocol,the communication mechanism of gateway and gatekeeper of Maipu company, the establishment of the administration of networks and the methods of improving the voice quality of IP telephone. At the same time, this paper particularly introduced the standard of designing multimedia communication system on the grouping exchange network, of which included the system structure of the H323 protocl,the protocol stack and the process of communication control described by the protocol. At last,the paper presents a Classified and Bnadwidth-Reserved Admission Control Algorithm。This paper's content comes from the author's knowledge learned in a communication company of Sichuan. At the same time, the author made use of the new knowledge of the development about IP telephone. By this way,the author wrote the paper.