3533

3339

كارشناسي ارشد

مخابرات

اصفهان: دانشگاه صنعتي اصفهان، دانشكده برق و كامپيوتر

1385

ده، 95، [II] ص.: مصور، نمودار

ص. ع. به فارسي و انگليسي

مسعودرضا هاشمي

حسين سعيدي

86/3/20

مهندسي برق و كامپيوتر

ID3339

به فارسي و انگليسي: قابل رويت در نسخه ديجيتال

AbstractExtending the university campus Public Switched Telephony Network PSTN networkand adding new capabilities to it need a new Public Branch Exchange PBX system withhigh cost The extension can be achieved using voice over IP VoIP on the universitycampus data network which reduces the costs and increases flexibility in providing newvalue added services Obviously the VoIP network should be interoperable with theexisting PSTN network To implement this solution design choices should be made todetermine VoIP signaling protocols servers and signaling protocols between the twonetworks using gateways or softswitches Issues such as reliability redundancy accessibility interoperability with other solutions QoS security and extensibility shouldalso be addressed In this thesis first we review possible commercial solutions provided bycompanies active in this market Since these solutions are usually expensive we thenpropose a solution based on free and open source softwares The proposed solution isbased on SIP protocol for signaling and uses SER server which is an open source solutionfor SIP proxy server as well as SIP redirect server and the registrar For communicationwith the data network beyond the university campus network and the Internet packetsshould pass the NAT Signaling protocols such as SIP have problems in passing NetworkAddress Translator NAT RTP Proxy is a suitable way to solve the NAT problem but itrequires that the RTP packets are also transferred through the server We propose asolution in which the RTP packets do not pass from the server

مسعودرضا هاشمي

حسين سعيدي