Comprehensive video network solution based on H.323 standard and its application
Summary
At present, H.323 has become a key point of video technology. This article describes how to build a multimedia network based on H.323 standards, build enterprise multimedia networks on intranet, realize video conferencing, video broadcasting, video surveillance, etc., and introduce various applications. .
Introduction Today, every modern company, regardless of its size, has built an intranet, with internal and external communication, data calculation, data access, data access, message delivery, and cooperation, but current These simple data interactions are no longer satisfied, and the data, voice, and image communication is hoped, so it is used to extend the network to the world with the company's existing infrastructure, and use the gateway and router technology to extend the network around the world. Become the focus of the entire industry. Since the H.323 standard is introduced, it is possible to achieve multimedia communication based on IP network, and VCON as a video conference leader, not only the first H.323-based video conferencing system, but also proposes a comprehensive video based on H.323 Network solution. H.323-based video network solution
This solution can make full use of the user's diversified network environment to build its enterprises for enterprises.
Industry Multimedia Net (EMI). In an intranet, data access, data access, file transfer, business management, and messaging can not only achieve multiple services such as interactive electronic whiteboard, application sharing, but also provide companies. Collaborative computing, video conferencing, video broadcasting, video on demand, video surveillance, and multimedia calls. This program is an open, scalable application platform not only adapts to the development needs of intranet, not only, but also provides multimedia applications on intranet, but also adapts to the future development and change of intranet / intranet, is a multimedia development, evolution, open multimedia. Application network.
This program mainly includes managing information services, video conferencing, video on demand, video broadcasting, multimedia calls.
The management information service part is based on the corporate intranet network platform that provides the most basic applications and services to companies, including: public information services, messaging services, collaborative work services, network data services, Web management services. At present, most companies can get these services through their existing intranet networks, such as inquiring corporate public information through browsers; sending and receiving email; participating in the online forum on intranet, idle chamber and other virtual space, conduct problem discussion, simple conference, etc. Need to work with the same sex; access the enterprise database, implement the application of business personnel, finance, document management database applications; access to directory resource access and management, authorization to information access, SNMP-based network management, etc. Because this is the most basic application of intranet, this article is no longer specified, and the other aspects can be introduced.
Video conferencing video conferencing is on the enterprise intranet, based on ITU-T H.323 standards and T.120 standards, you can implement some-to-peer video conferencing between individuals, and you can also realize multi-person video conferences, and In the future, adapt to a number of participants, support H.323 standards and RFC1112 (IP Multicast) multi-point broadcast conference. The H.323 standard is made to make users a reality in the Intranet / Intranet on the packet-based video conference on the Intranet / Intranet. At the same time, T.120 standard is the function of H.323 terminals and expands the functions of the data conference, realizing a multi-point electronic whiteboard (T.126), multi-point file transfer (T.127), multi-purpose sharing (T.128 The data conferencing function, so that the company intranet user truly implements face-to-face communication and collaboration. It needs to add the following sections from the existing intranet: • H.323 video terminal, including: Software upgrade H.323 codes (compatible H.263 video algorithm and g.732 .1 audio algorithm), camera , Hand-held microphone or microphone / speaker, MeetingPoint 3.0 or higher software. · H.323 multi-point conference parts, including: H.323 multi-point controller software, can be installed on conference terminal, MCU, gateway, network gate, implementation of distributed multi-point conferencing; H.323 multi-point processing The device, realize sound mix, image switching and other sound / video processing; H.323MCU, achieve complete multi-point conference functions, such as management, definition, arrangement, and control of multi-point conference, establishment and control of channels; sound or images Mixing, switching, and mode selection, etc., and IP multi-plug software to achieve a wide range of interactive multi-point meetings. · Gatekeeper, mainly in software form, mainly responsible for the definition and management of the H.323 conference domain; H.323 username and address translation; H.323 Conference terminal registration, registration and status Display (RAS message); H.323 network bandwidth management and control; H.225 call signaling and H.245 Control signaling; a proxy for H.323 calls. · H.323 / H.324 / H.320 / H.310 Gateway, mainly implementation of the H.323 protocol and the transformation and processing of the H.324 / H.320 / H.310 protocol, implementing H.323 video The interconnection of the conference network and other nets. At the same time, the H.323 call agent can be combined, and the H.323 call is also passed to other online. In addition, video / audio accessories such as auxiliary cameras, video switches, external allocation microphones, and speakers. This solution is to ensure the data security of the H.323 conference through H.235, by setting the H.323 proxy server to ensure the security access and control of the H.323 conference, the proxy server implements the H.323 call and the user's inspection, so that Legal H.323 calls and users can perform H.323 connections through enterprise firewalls, and prevent illegal H.323 user calls and partial restricted H.323 user calls. With the CMS centralized network management system, users can use Microsoft Internet Explorer and Netscape Navigator on any workstation to manage, define, arrange, and control the meeting. The video broadcast video broadcast system is based on real-time data transmission mechanism - doETF RTP, RTCP protocol, RSVP protocol, and IP multicast protocol IETF RFC1112.
RTP and RTCP guarantees the time tag of real-time multimedia data streams and controls delay jitter, and RSVP retains bandwidth and provides service quality for real-time multimedia data streams. IP multicast can broadcast an IP package to a network segment or site that requires this package (see RFC1112 protocol), if a site is not a group member of this package, then "listening" does not reach this package. This ensures that only one multimedia data stream is flowing on the network or network segment, and is listened to and copies, and avoids the broadcast storm brought by no-purpose broadcast and increases the CPU processing burden of each station, so it is different from Single-point communication (Unicast), which is different from no-purpose broadcasts (BROADCAST). It is a purposeful multicast. Video broadcasts can support: · Real-time TV news broadcasts, users can feed the TV station in real time through video servers in real time in real time, let thousands of users watch TV programs through the workstation And support multi-channel programs. The video format supports INDEO, H.261 and MPEG; audio supports LPV, INDEO, GSM, and MPEG. · Real-time distance education and training, users can conduct real-time employee training and distance education on intranet through video broadcasting. Users only need to use camera and microphones, or use a plate making good training materials tape or VCD / LD to feed the audio and video flock to the video server, broadcast training content to the audience on the entire intranet. The viewer can make a question from the teacher through a questioner, and can watch the teacher in the way, and can watch the speaker with PowerPoint speech film. In addition, there are applications such as internal communication, real-time securities / stock information transmission. The video broadcast system consists of several parts: • Video broadcast server, including MPEG or H.261 video encoding card, audio coding card, and server package, which makes audio / video streams to intranet, responsible for video / audio Coding work. · Video broadcast viewer, the viewer is a pure software decoder running on ordinary user multimedia workstations. Users can easily view TV programs, training content, company lectures such as each channel. · Video Broadcast Program Guide (optional). The Program Guide is based on the browser interface, allowing users to easily arrange and set software for program channels. · Video Broadcast questioner (optional). It is a software that can be easily enabled by entering the text of the text by using the way of tapping the text, then communicating into the teacher in text, and communicating two-way communication. · Video Radio Film Breader (optional). It can easily broadcast the speaker with PowerPoint film to the audience. The video surveillance video surveillance system is capable of completing digital image monitoring of local or remote controlled sites with corporate intranet. The user can use the digital line, or use the modem to connect the controlled site to the intranet of the enterprise. After compressing the distal image encoding, the lower bandwidth is used to send to the master center via Intranet. The main control center decodes the remote screen and monitors the remote site. The video surveillance system consists mainly of the following parts: • Remote controlled host, mainly including image encoders, responsible for compressing remote monitoring live video streams and control signals. · Remote video switches are responsible for control and switching between multiple cameras of the far-end monitoring. · Remote camera, responsible for the collection of video signals in the far-end monitoring site, and the remote field can be configured with multiple field cameras. · Decoding the master, as needed, can set one or more decoding main controls in the main control center, decoding video streams from the remote monitoring site, and on the TV wall of the main control center or on the monitor Display distal monitoring site. Multimedia Call Center
Multimedia Call Center System provides convenient call services to users on intranet, and users in the enterprise intranet can via H.246 gateway (H.320 / H.323 / H.324 / H.310Gateway) and outside ISDN network, POTS online users implements some Q.SIG-based call supplement services (H.450.x), for example:
· Direct call into service (DDI). ISDN / POTS users can call to the H.323 end user on the enterprise intranet through the switches and gateways. The H.323 terminal can operate in an audio state, call with users on the public network.
· Direct callout service (DDO). The H.323 terminal on the enterprise intranet can also use the dial-up call to call the H.320 terminal, H.324 terminal, phone or mobile phone on ISDN / POT, to implement a call.
• Call Transfer Service. When ISDN / POTS / H.323 users call a H.323 terminal on the enterprise intranet online, the H.323 user can transfer the call to other ISDN / POTS online phones, mobile phones, or other H.323 users. on. vice versa.
· Call forward. When ISDN / POTS / H.323 users call a H.323 user on the enterprise intranet or intranet online, if they are busy or the H.323 user does not answer the call to the call center to pre-set user Other ISDN / POTS online phones, mobile phones, or other H.323 terminals. vice versa.
• Call Complete. When the user opens a H.323 terminal or mobile phone in advance, the information in the user's unprocessed voicemail can be submitted to the H.323 user or a preset mobile phone.
· Caller ID). When the user calls the H.323 terminal call, the H.323 terminal can display the calling party number - IP number or phone number. System needs to be added:
· The gateway, responsible for the audio, video and control multiplex protocol transformations of H.320, H.323, H.324, and also combat IP / E.164 address translation, Q.931 call, act as a call relay transfer device .
· Call center, providing call forwarding, call commit, call, calling identification, voice mail, H.323 call redirection, etc.
· Enterprise intranet and corporate PBX interface.
Advantages of H.323 Comprehensive Video Network Solutions
Comply with the ITU H.323 standard. Combined with corporate intranet, realize audio, video, data simultaneously, without requiring another special video conference network, saving user investment. Entering top video quality 30 frames / sec, there is no need to pay a communication fee in the enterprise network. Seamless connection with the video surveillance system, can be used through MCU, but also remotely control multiple sets of remote lenses, watching the site. No use of ISDN or DDN lines, easy to install, save investment. The networking is more convenient, there is no need for a dedicated video gateway, using a normal router to connect to the remote network. Web users share remote access lines and devices such as routers, gateways, etc., cost-effective. With standard technologies, the PCs of the are platform, no special hardware and hardware, do not occupy too much system resources. The networking is more flexible, and the extension is easier to protect users.
Application field
The distance teaching system remote teaching system is enabling education and professional training services to each person, and is not limited by unfavorable factors such as financial and geographical. Through remote teaching systems, students can have more opportunities to participate in special education, continuing education, professional training, and take into account all the advantages of traditional teaching. Students and educators have the opportunity to communicate (in audio-visual forms), and cooperate in real time to work together with video conferences. The implementation of remote teaching is simple, transcending geographic boundaries, whether it is cost-effective for teaching institutions or students. Distance teaching is widely used in the improvement of urban and rural education, teachers and administrative staff training. For enterprises, using remote teaching systems, employees can get training at the same time and enrich the knowledge of the latest products and technology as soon as possible, but do not cost high training fees. With VCON's software development tool VDK, users can develop their own remote teaching systems to meet their special functional requirements. Application, campus and campus contact, on-site training, special seminars and forums, virtual universities, disabled people distance education, rural or suburban education. Safety Monitoring System Security Monitoring System can remotely monitor the situation in different regions without setting up special personnel, can continue to monitor, greatly reduce the cost of employed a large number of security personnel to patrol at different locations. VCON's video surveillance system based on the ISDN, LAN network, allows a central security command center to monitor multi-objective anytime, anywhere. The center command station can control the camera operation of the remote unmanned location, using a high-performance camera to do 360 ° monitoring, monitoring the system with password, and has a simple and easy to use user interface. In addition, real online conferences can not be implemented on monitoring systems, so that security people can be discussed to face important matters. Because more and more business customers need to adapt to security monitoring systems in different fields, it requires economic, efficient, and VDK development tools to help customers customize their own security monitoring systems to implement a particular area requirement. Application of safety monitoring: surveillance parking, corridors and entrances; remote control enters buildings; control and management; monitoring remote gates and connection zones; commercial location or residential monitoring; public supermarkets, conference venues or critical zone internal and external monitoring , Traffic monitoring. The remote wealth management system remote wealth management system allows financial institutions to provide effective personalized services to customers and agents while saving time and money. The remote wealth management system has developed a wide range of specialization and personalized services, so that banks or financial institutions can provide e-banking services all day 24, easy to operate, private, corporate customers, have a quick answer to relevant bank issues . Customers can enjoy direct contact with the remote financial experts, quickly handle loans, credit card issues; enjoy personalized services and immediately understand detailed personal bank information and financial data. With software development tool VDK, financial institutions can order special electronic banking applications for customers, establish multimedia public touch terminals, and anywhere offers users with comprehensive multimedia banking services. Application of remote financial system: Banking service in remote family or office location; service customer multimedia public touch terminal; remote contact with bank experts and senior people; obtain personal account information and financial statements; bank customers real-time video identity authentication and inspection Union decisions with colleagues in the field; loan application and credit approval; personal bank. The telemedicine system remote medical system can make medical experts or health workers to remotely consult patients.
And can make patients can get effective, economical medical services regardless of their land. Through telemedicine systems, medical data, radiographic images, medical records, and patient files can be passed from one place to another. Surgical experts can be discussed and collaboratively from geographical restrictions. Using Software Development Tools VDK, you can customize your own remote medical system according to a particular medical requirements. You can use professional equipment such as remote camera, graphic scanning, and micro-camera devices to assemble your telematics and easily access medical image library and database. Application of telemedicine system: patient consultation; interactive telemedicine and teaching; patient medical education forum; medical administration; family health; hospital internal meeting or hospital to hospital meeting; for rural or remote areas such as military base, labor education, etc. Provide health care. (Li Ping)
