Introducing VoIP Networks参考.ppt

Describe Cisco VoIP Implementations Introducing VoIP Networks Benefits of Packet Telephony Networks More efficient use of bandwidth and equipment更有效的使用带宽和设备利用率 Lower transmission costs较低的传输成本 Consolidated network expenses整合的网络成本,无须使用单独设备实施VOIP Benefits of Packet Telephony Networks (Cont.) Improved employee productivity through features provided by IP telephony:通过IP语音技术可以有效的提高员工生产率: IP phones are complete business communication devicesIP电话是完善的商务通讯设备 Directory lookups and database applications (XML)基于XML技术的目录检索和数据库应用 Integration of telephony into any business application使用商务应用程序很轻松的集成语音数据 Software-based and wireless phones offer mobility.使用基于软件和无线的电话技术能够为客户提供移动特性 Access to new communications devices (such as, PDAs and cable set-top boxes)访问前瞻性的设备,比如掌上电脑(PDAs)等 Packet Telephony Components Two Basic Methods for Voice over IP Analog Interfaces Digital Interfaces Stages of a Phone Call Distributed Call Control Centralized Call Control Summary Companies can benefit from a common infrastructure that serves voice and data. Advantages of such converged networks include lower costs, more efficient use of available bandwidth, and higher productivity. A packet telephony network consists of endpoints (such as IP phones, software phones, and video endpoints) and voice network devices (such as gateways, gatekeepers, conference bridges, call agents, and application servers). A voice gateway can use FXS, FXO, and EM interfaces to connect to analog equipment, such as phones, PBXs, or the PSTN. A voice gateway can use BRI, T1, and E1 interfaces to connect to digital equipment, such as ISDN phones, PBXs, or the PSTN. A voice call consists of three stages: call setup, call maintenance, and call teardown. With distributed call control, each gateway has local intelligence to route calls, while with centralized call control, a call agent makes call routing decisions on behalf of all the gateways that are controlled by the call agent. Cisco Network Academy. All rights reserved..