With the rapid development of the Internet, our work and lifestyle are gradually changing. In 1995, the world's first software product "Internet Phone" that can make long distance calls through the Internet came out, and then a brand-new voice over IP was carried. The method of communication is presented to us. With the in-depth development of this technology, IP voice has gone through three stages: PC to PC, PC to phone and now phone to phone. In China, ADSL has been the most widely used as an Internet access method since 1999. The advantages of bandwidth / price ratio and simple access characteristics make ADSL the first choice for broadband access for homes, enterprises and institutions. While Internet services and mail services are widely used, many units hope to realize voice communication through ADSL lines to reduce office costs and increase line utilization. Although voice communication can be achieved through ADSL lines and VoIP equipment, because its voice packets are transmitted through a wide area network, its implementation quality and security are much worse than that of a private network, so systems such as governments generally do not choose ADSL. For enterprises, ADSL is the cheapest access method, and its implementation quality and security are not as high as those required by government and security systems. Therefore, enterprises are more willing to choose ADSL + VoIP voice solutions. The following figure is a typical topology diagram of using leased ADSL lines to build a voice network. Generally speaking, enterprises that need to build voice networks have cross-region branches, and the central point in the figure is generally the headquarters of the enterprise. Since the number of headquarters staff is generally relatively large and requires a relatively large number of phones, you can choose to configure a VoIP gateway with a relatively large phone interface. Of course, if the headquarters already has a program-controlled switch, only one VoIP gateway with a trunk interface needs to be configured. In addition, you need to configure a gatekeeper at the central point (the gatekeeper can be placed in any place where the network can reach, but the most convenient is to put it in the central point) to complete registration, call acceptance, address translation, bandwidth control and other functions. Because each remote end is connected to the center through the WAN, the central gatekeeper needs to configure a fixed IP address (you can apply to the ISP). The picture above shows the KVP6032 VoIP gateway at the center, which can provide up to 144 phones, which can meet the needs of the general center. KVP6032 also has built-in gatekeeper, proxy and MCU functions. The embedded gatekeeper on the one hand protects user investment and improves application flexibility, on the other hand it provides a high degree of integration and application stability. The built-in embedded agent can realize VoIP and VoIP calls in the network environment of NAT and firewall without the help of external equipment. Built-in MCU can realize multi-party IP telephone conference function. In each branch, only one VoIP gateway needs to be configured after the ADSL Modem, and the number of telephone interfaces or trunks of the gateway is selected according to the actual situation of the enterprise. In the picture, two VoIP gateways, KVP6011 and KVP6017, are configured for branch offices, which can provide 4-way and 8-way telephones or trunks, respectively, which is suitable for the application of small branch offices. After such a simple deployment, and related settings of the VoIP equipment of each branch and headquarters, IP voice communication between each node can be achieved, and the public network is used to transmit voice completely, saving telephone charges. The VoIP gateway can also directly access the trunk line to connect to the PSTN network. Telephones hung under the VoIP gateway can choose internal or external lines through different dialing settings. In addition, the use of the relay function can also realize the telephone communication from the local to the external network and the local external network to the external network. In this way, long-distance charges can be saved, and only the calling party can pay the local telephone charges. Of course, when choosing a VoIP product, enterprises also need to consider device compatibility, voice processing capabilities, QoS capabilities, and other related performance to ensure that they provide good voice communication to the maximum extent in existing networks. rechargeable batteries,golf cart batteries,Car Battery,replacing car battery SUZHOU DEVELPOWER ENERGY EQUIPMENT CO.,LTD , https://www.fisoph-power.com