【 Weak current college 】 online video conference system should be how to plan

Video conference system is basically divided into three categories: desktop, xiaozuxing, groups-/meeting room. How to plan Web video conferencing system? there are three: select the appropriate client device, to calculate the bandwidth requirements for LAN, WAN link connected. Video Conference design in a nutshell can be divided into three steps: select the appropriate client device, calculate the LAN bandwidth requirements, connected to a WAN link, and then you can start video conference. Client device based on the use of different, current video conference system is basically divided into three categories: desktop. Desktop video conferencing client is for personal use by the client system. Its selling price based on the hardware of the system to the $ 3000 US dollars, based on the software of system is priced at about $ 150. Generally this type of system is the use of IP. Xiaozuxing. Some xiaozuxing client is a dedicated device, priced at $ 3000 in General to 12000, nor the PC-based, price is generally between $ 6000 and 14000. This type of client are very easy to configure and use. They generally run in ISDN or IP. Groups-/room type. This type of client you can deliver high quality video communication, of course, price is highest, each system must have at least $ 10000. They also run on the ISDN or IP. LAN speed video conferencing systems can be based on the existing PSTN, private IP network or the Internet, the system typically require 300kb/s to 400kb/s of bandwidth to transfer including audio, video and control signals, interactive video data communication. H.323 protocol does not require a dialogue (Session) of two or more users to receive data at the same speed to send data. Processing power of a lower user maybe only 100kb/s to decode, but due to decode to processors of capacity requirements are not high, it also can be done on 300kb/s data decoding. Video conference system bandwidth use is symmetric. And full-duplex networks such as ISDN, Ethernet, ATM, and TDM networks, although the network bandwidth is symmetric, but the network capacity is in accordance with the one-way transmission bandwidth to defined. The user must correctly estimate your network need support while the number of the dialogue and to calculate its desired end-to-end bandwidth. A T1/E1 line about can provide one-way 1.5Gb/s of bandwidth, so are well placed to implement two 512kb/s or three 384kb/s video conferencing. Multipoint video conferencing (three or more places to see and hear) bandwidth is in accordance with each point-to-point dialogue of bandwidth to the calculation of respectively. Multipoint session can run on IP or ISDN, some video conference system can also support both network. Multipoint conferencing products can be based on the software you can also use the special acceleration hardware. By changing the settings you can provide different bandwidth requirements. When an end user to log on to a multipoint session, each user's maximum bandwidth becomes a total system bandwidth and participate in meetings of the number of users. WAN connection is currently on the market of large video conference system approximately 80 per cent is directly connected via ISDN, in addition there are less than 5 per cent system uses the ATM, the rest are using IP. If the system you want to connect to the corporate foreign locations it is best to use ISDN. General IP network capacity is not enough, each month only two to three hours of the call. If you want to use ISDN and use a centralized user management or system management, users must be established for each device, Ethernet connectivity and management packages installed on the server. ISDN also has its limitations, including: • wide coverage not installed; * not easy to set up and manage; • easy because a single point of failure, a service interruption occurs; • cost increases with the distance; • support only one telephone service, that is, the more Conference; • ISDN video call cannot call hold, call transfer, also does not support video mail. IP network using H.323 standard compatible Terminal products, or other technology may transfer data only IP network into support business video conferencing service network. If you want to set on the IP network for more than five or six system, you need to add a management platform for centralized user management and network management. There are many companies working to develop new management software, management software, although the functions and features differ, but they will provide the address of the management function, according to each user or device to set performance standards, even reducing the excessive bandwidth consumption caused by the application of the data flows. QoS issues in LAN using QoS to protect those who are sensitive to service application integrity. Most major network equipment manufacturers support generic QoS standards. The user must understand their own backbone network uses what QoS, if the local loop of QoS agreement or mechanism and backbone networks, enterprise networks must be installed within the QoS conversion software. QoS problems solved in agreement, the user would also like to add additional network to ensure that the video does not block other application data. In order to avoid clogging of the phenomenon, the network administrator on each switch and to route be fragmented and bandwidth management to restrict the high priority video traffic in aggregate. In addition to bandwidth management and QoS settings, there are other problems. One of the biggest one is how to enable real-time video communication through the firewall. The firewall should be able to provide H.323 proxy or use control channel to determine which dynamic dialogue using Socket to H.323, and only in the control channel activation period allows data to be passed. Emerging services due to the nature of the video conference is communication and most of the existing system is not based on IP, so users often encounter system through different networks and the need for protocol conversion. When video conferencing system to simultaneously run in ISDN and IP networks, the system must use the networkGateway. When the video conference system for collective meeting, the user can configure the system to do some optimization. For example, by setting the IP multicast and smart client network can do not need multipoint control units (MCU, MultipointControlUnit) effectively supports multipoint conferences. When using IP multicast to realize multipoint session, each client sends a packet stream to the IP multicast groups the other all machines can receive these grouped data. In this way, the system of bandwidth consumption than the sender for each receiver to send a packet stream of small lots. Next generation video conference system features a video conference with media streaming system, through a media streaming server for video conference from a codec to multiple remote browser for broadcast or video conference record in media streaming server for playback. The number of cost according to the Terminal, client type and network, video conference system for the lowest price reached $ 100 per seat, Supreme over each meeting room $ 15000. Specific costs depending on number and needs of the system. General ISDN-based systems to support IP, only supports IP system cost than a system based on ISDN low cost several hundred dollars, this is because it requires less system components. Management software prices are based on the site, the number of licenses to determine license, there is a $ 250, one of the 40 dollars, while others do not limit the number of licenses. Large enterprises use of enterprise video conferencing system in General with system software and hardware, each have more than 10 million.