Deploying IP voice on a wide area network

Because the scale of the enterprise is different, the application emphasis is different, the construction of the enterprise mixed network has no unified model. However, the integration of data, voice, video, storage, and all business application systems on a single IP network is common. The construction of the hybrid network should be unified planning, staged modular implementation.
　　
　　
　　
The construction of Enterprise WAN IP Telephone
　　
After the enterprise establishes the WAN, the branch office to the headquarters connection bandwidth is 128kbps to 2Mbps, such high bandwidth has laid the solid foundation for the enterprise to carry on the data, the voice and the video application. IP voice communication on the Enterprise wide area network will be removed from the enterprise nationwide long-distance fee: The VoIP Gateway of the enterprises nationwide will be connected to the local public telephone exchange network, any city covered by the enterprise can realize the telephone communication with the other cities connected by the Enterprise wide area network. At the same time, the realization of Enterprise National IP Voice, will establish a nationwide centralized customer service center to lay the foundation.
　　
Since the corporate headquarters typically has a traditional PBX telephone switch, Cisco 3725 is configured as a voice gateway at Headquarters and connected to a PBX through the E1 interface. If the enterprise has a number of branches in the country, each branch office does not need to configure the PBX. According to Cisco's Avvid architecture, Cisco CallManager can be deployed at headquarters to centrally manage all call processing across the country. Connected to the city's public telephone exchange network in the city where each branch office is located, the NM-2V and VIC-2FXO modules are configured on the Cisco 26XX or 36XX series routers of the branch office to provide 4-way telephone analog relays, Configure nm-hdv-1e1-30 or nm-hdv-2e1-60 to provide 30-way or 60-way telephone digital trunking. In each branch, according to the needs of the communication, if the cadre IP telephone, such as Cisco 7960, also configured several IP telephones at headquarters. IP telephones can be connected directly to the network switch.
　　
Configure a set of IP PBX system call manager clusters at Enterprise headquarters, CallManager includes three MCS-7835 servers. One serves as the primary server, primarily for centralized processing of all IP voice calls at Headquarters and branch offices, the other as a backup server, and one for publisher, TFTP, and DHCP servers. Another important function of CallManager is to control and manage the bandwidth of the WAN. For example, each branch office can be used as a call area at the headquarters CallManager, and a certain bandwidth is customized for each call area's voice call, so that CallManager can track the utilization of WAN bandwidth per branch office.
　　
Cisco CallManager extends corporate phone features and functionality to packet phone network devices, such as IP telephony, IP voice gateways, and multimedia applications. It is installed and running on the Cisco MCS and is managed and configured through a Web browser. CallManager and all telephony, gateways, and applications can be distributed across IP networks, providing a distributed, virtual telephone network that greatly enhances the scalability and availability of enterprise IP telephony solutions.
　　
Cisco CallManager supports user features such as automatic answering, call forwarding, hotline, call keeping, call waiting, calling line recognition, caller name identification, direct inward/outward dialing, telephone catalogue, distinguishing vibration ling, multi-party conference telephone, etc.
　　
Cisco CallManager provides CTI support for full JTAPI applications and has developed JTAPI applications such as IP-AA, IP automatic operators, IP automatic voice response, IP softphone, IP software telephony, IP contact Center, IP Call center and so on.
　　
　　In addition, using Cisco Voice Manager (CVM) makes it easy to configure VoIP dial plans and save configuration time. The CVM call Detail logging (CDR) feature enables users to get the same detailed VoIP voice traffic information as traditional PBX traffic