從電信級應用的角度出發，對公眾電話網和語音IP電話進行了比較研究，其重點包括交換方式、信令、尋址、路由四個方面。通過分析比較，可直觀地看出IP電話在交換技術、帶寬占用、系統開放性、通信成本、系統靈活性等諸方面優于傳統的公眾電話網；對IP電話與公眾電話網資費比較，闡述了IP電話價格的競爭力，并給出了用戶、IP電話營運商、IP電話技術等幾個要素循環互動的模型。結果表明，IP電話將成為長途通信的主流應用，公眾電話網與IP電話將逐步走向融合。
關 鍵 詞 IP電話; 公眾電話網; 比較; 資費

Abstract From the angle of applications given by public telecom enterprises (China Telecom, China Unicom, etc.), the comparative research between traditional PSTN and VOIP has been done in this paper. The switching technology, signal system, protocols as well aw routines were compared and analyzed. The results show that VOIP were much better than PSTN in switching technology. Costing, band consuming, openness and flexibility. Based on the latest official Telecom costing files, the costing comparative results was given out between VOIP and PSTN. The interactive effecting model was given out in this paper. The opinion that VOIP and PSTN should be treated as a whole system was also pointed out.
Key words IP phone; public service telecommunication network; comparative; costing