ddn

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computer communications technology, the rapid development of economy, finance, securities, customs, foreign trade and other groups of data users and leased line departments, units Click here to add captions substantial increase in the database and its search business has rapid development of modern society's dependence on telecommunications services is growing. DDN (Digital Data Network, digital data network, the Internet is usually referred to line mode) is suitable for the business development of a transmission network. It is the tens of thousands, hundreds of thousands of digital optical cable as the main circuit, digital circuit through the management device, constitute a high transfer rate, good quality, network delay is small, transparent, high-traffic network data base.

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What is DDNDDN principle business services DDN DDN DDN network describes the advantages and disadvantages DDN network diagram of the structure of DDN DDN network features network-level Chinese public digital data network, DDN Network Application Network Status DDN DDN network operations network in the application of computer networking in the DDN network applications in the financial industry in the DDN network applications in other fields of development Conclusion DDN network what is what is the DDN DDN [1]? It is the use of digital channels transmitted data signal data transmission network. (Digital data network is an optical fiber, digital microwave or satellite and other digital transmission channel multiplexers and digital cross consisting of digital data transmission network, it can provide users with various rates of high-quality digital data digital private power

Network (ddn

Road and other new services to meet the user set up in the high-speed multimedia communications and the need for computer communication networks, mainly consists of six parts: optical or digital microwave communication system; intelligent node or hub device; network management system; data circuit-terminating equipment; subscriber loop; client computer or terminal device.) Its main role is to provide permanent and semi-permanent connection of digital data transmission channel, both for communication between computers, can also be used to transmit digital fax, digital voice, digital image signal,[url=http://www.buy-ugg.us/][b]title=UGG Boots Outlet[/b][/url], or other digital signals. permanent connection of digital data transmission channel is the user establish a fixed connection, transmission rate constant of exclusive bandwidth of the circuit. semi-permanent connection of digital data transmission channel for the exchange of non-users, but users can apply to their management by the network's transmission speed of data transmission destination and the route to be modified. network operators to provide customers with a flexible digital circuit rental business, for each form their own private network industry. DDN provides a semi-permanently connected dedicated circuit is dedicated for all users or private network users based telecommunications network, can provide high speed line, point to point digital transmission . DDN itself is a data transmission network, to support any communication protocol, which protocol determined by the user (such as X.25 or Frame Relay). The so-called semi-fixed means the user need to temporarily establish a fixed connection to the users, dedicated applications, the connections have been completed, and the connecting channel data rates, routing, and the use of network protocols at any time according to the need to apply changes. DDN principle [2] · DDN is the use of digital channels to provide semi-permanent connection circuit to transmit data signals based digital transmission network. · DDN nodes through cross connections within the network to provide users with a fixed, fully occupied by the user alone, the physical channel digital circuits. users regardless of whether the transmission of data, the channel is always the user exclusive, unless circuit network remove this user and this is a circuit-switched mode.

digital data network (ddn

DDN can provide users with 2.4k, 4.8k, 9.6k, 19.2k, N * 64 (N = 1 ~ 31) and 2048kbps rate transparent dedicated circuit DDN user terminal can be asynchronous terminal (DTE),[url=http://www.moncler-online.us/][b]title=Moncler Sale[/b][/url], computer (PC), can be a local area network is transparent to transmission network DDN: 1. provide users with a physical channel, and do not make any changes to user data, direct transmission, the use of resources and there is no agreement on the exchange of additional overhead. 2, the user's access request is to provide the physical interface and network physical interface match. DDN Business Services main

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business is to provide customers with multi-rate digital data lines for LAN / WAN interconnection, the interconnection of different types of networks such as images and video conference services transmission, packet switching network users while providing access to packet switched network data transmission path. DDN DDN way the advantages and disadvantages The main advantage is the use of digital

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circuit, the transmission quality high, the delay is small, the communication rate according to the need to choose between 2.4kbps--2048kbps. ② transparent transmission circuit, and automatic winding, high reliability. ③ line should be spent, can carry fax, Internet access, video conferencing and other multimedia services. ④ easy to set up a virtual private network (VPN), to establish their own network management center to manage their own network. The main drawback is the use of DDN dedicated Internet access, need to rent a dedicated communication line, rental costs too high, by no means ordinary individuals can afford. DDN network structure of DDN DDN network introduced by the digital transmission network and the corresponding digital circuit composed of cross-multiplexer which, mainly in the optical transmission of digital transmission circuit-based, digital cross-connect

digital data network (ddn) extension

multiplexing equipment for semi-fixed for digital cross-connect circuits and sub-rate multiplexing. DTE: Data Terminal Equipment - DDN network access client device may be a LAN, through the router connected to the right side, it can be a general asynchronous terminal or image devices, and fax machines, telex, telephone and so on. DTE and the DTE is completely transparent transmission between. DSU: Data business units - can be a modem or baseband transmission equipment, and time division multiplexing, voice / digital multiplex equipment. DTE and DSU's main function is to access and take out business. NMC: Network Management Center - you can easily configure the network structure and operations real-time monitoring of network operation, network information, network node alarms, line utilization, etc. collection, statistical reports. DDN network-level network diagram in accordance with the basic functions of DDN network can be divided into the core layer, access layer, user interface layer The core layer: 2M circuits, constitute the core of the backbone nodes,[url=http://www.uggsbootsclearance4u.com/][b]title=UGG Shop[/b][/url], perform the transfer function of network services, including Frame Relay service switching function access layer: for the DDN to provide various types of business sub-rate multiplexing and cross connect frame relay service user access and features local frame relay, and voice compression / G3 fax user network. User interface layer: provides the user network adapter and the adapter features, such as small-capacity time-division multiplexing equipment. DDN network features ( 1) The transmission rate is high: in the DDN network within the digital cross-connect multiplexer to provide 2Mbps or N × 64Kbps (≤ 2M) rate digital transmission channel (2) transmission of high quality: a large number of digital trunk transmission system using optical fiber , exclusive of fixed connections between users, network latency small. (3) the agreement is simple: the use of cross-connect technology and time division multiplexing technology, a high degree of intelligence from the customer premise equipment to complete the protocol conversion, itself not subject to any order constraints, is fully transparent network, for various types of data users (4) Flexible connection: You can support data, voice, image transmission and other business, it not only can the user terminal equipment to connect, and can also user network connection, to provide users with flexible networking environment (5) circuits and high reliability: the use of circuitous routes and alternate ways to make the circuit safe. (6) network operation and management is simple: The network control and supervision of network operations , the business quickly generate the Chinese public digital data network, status of Chinese public digital data network backbone (CHINADDN) officially opened in 1994 and has more cities around the country and some economically developed cities in the county. It is operated by China Telecom , to provide services to the community's public information platform. CHINADDN network structure can be divided into national DDN, provincial DDN, municipal DDN. DDN national networks (the major backbone of the core area) main function is to establish between the inter-provincial business logical routing, providing long-distance and international export business DDN. provincial DDN (provinces) main function is to establish the municipalities across the province between the business logic routing, provide the province's long-distance and out of province DDN business. municipal DDN (the the local level), mainly due to a variety of low-rate or high rate for business users to reuse them and pick out the access and the establishment of a logical route between each other so that the domestic and foreign users to transmit information to each other through DDN line. levels of network management center is responsible for the generation of user data, network monitoring, adjustment, maintenance of alarm handling. DDN DDN network to provide network application business as DDN network is a fully transparent network, can provide multiple services to meet all kinds of the needs of users, providing rates within a certain range (200bit/s-2Mbit/s) optional large amount of information in real-time strong high-speed data communication services such as LAN interconnection, and medium-sized host interconnect, computer internet business provider (ISP), etc.. h for the packet-switched network, the Internet and other public computer to provide relay circuit. h to provide point to point, multipoint services for financial securities companies, research and education system, government departments DDN leased line establish their own private network. h to provide Frame Relay services, expanding the business scope of the DDN. user through a physical circuit can simultaneously configure multiple virtual connections. h to provide voice, G3 fax, image, intelligent user telex communications. h to provide Virtual Private Network service. a large group you can rent more than one direction, a greater number of circuits, through their own network management station, for their management, their distribution circuit bandwidth to form a virtual private network. DDN network of computer networks Application DDN transmission network as a computer based data communication, to provide point to point, multipoint, large-capacity information transmission channel, such as the use of DDN network composed of national customs, foreign trade system network provincial customs, first through the provincial foreign trade center DDN network, a long-distance relay, DDN network backbone to reach the core node state by state across the network management center in accordance with the destination of distribution of required accessible routes, the establishment of a flexible national customs trade data transmission network and through international export Bureau, exchange information with overseas companies, foreign trade transactions can be carried out without leaving home. In addition, DDN lines for LAN interconnection applications are more widely and some overseas companies to set up offices around the country formed the first local area network within the through routers, network equipment through local, long distance and corporate headquarters DDN LAN connected, resource sharing and file transfer, transaction processing and other services. DDN network applications in the financial industry not only for weather DDN network, public security, railway, hospitals and other industries, also related to the securities industry, banking, engineering, real-time Gold strong data exchange through DDN network bank ATMs (ATM) connected to the banking system, a large mainframe computer. Banks are generally leased 64Kbps DDN operating point of each line to the ATM machine for the city and the national networking in user withdrawals, user authentication, the amount extracted, balance inquiries and other work is done by the bank host, so that to form a reliable, efficient information transmission network. securities issued by the DDN network market, the approach of many brokerage securities company DDN leased line interconnection with the Securities Trading Center, real-time quotes on the big screen with the Securities Trading Center and the dynamic changes in the securities market to change while far away in different places of the investors are also able to synchronize the local securities companies to determine their own capital to invest. DDN network applications in other fields DDN network as a data service bearer network, not only can the user terminal access and interconnection to meet user network, and applications to expand the scope of information exchange in all walks of life, all areas of application is wider, such as the use of wireless mobile communication network after the DDN network, improve network reliability and rapid self-healing capabilities. VII signaling network networking, high-quality video and telephone conference, the future development of value-added services are based on the DDN network. DDN network development in

digital network equipment data network (ddn) extension

constantly upgrading, people will not stop the application of new technologies in a single network for voice or data transmission platform of multimedia communications applications are popular. Video on Demand (IP / TV), electronic Business (E-Business), IP-Phone, e-shopping and other new applications are promoting these applications on the network bandwidth, delay, transmission quality and higher requirements. DDN exclusive resources dedicated channel will cause part of the network waste of resources, and applications for these new technologies will bring issues such as the bandwidth becomes too narrow, therefore, DDN network technology must continue to move forward from the network needs to build a modern point of view, the existing DDN's function should gradually be strengthened, such as bandwidth on demand to provide users with the ability to; to adapt to a variety of business communications and improve the channel utilization, you should consider statistical multiplexing; network management system to improve the openness and user interaction with the network capabilities; can used to improve the relay rate approaches to improve the current relay node between the rate of 2Mbps; rate of the corresponding user access layer can be greatly improved, in order to adapt to new technology in the DDN network of high-bandwidth applications; can make a DDN network platform a multi-service platform in addition to the current extension of the existing frame relay and voice switching services, G3 facsimile services, but also the most advanced equipment and technology continues to transform and improve the DDN network, the introduction of transmission and switching, transmission and access, etc. aspects of change, to produce a switched virtual circuit DDN equipment actively engaged in value-added network services, such as database retrieval, visual graphics and other services by simply letting the circuit or port type changes to the messaging service, for the information society development to make contributions to a deeper level. Conclusion DDN is still a lot of units used to implement a WAN connection means, in particular for the requirements of a steady flow of reliable and secure transmission of information especially in the application environment, but for the sudden flow of information transmission, its economic performance somewhat less certain. DDN networks to data communications technology, digital communications technology, optical fiber communication technology, digital cross-connect technology and computer technology combined organically through the development, DDN-end applications ranging from simple data Communications expanded to provide and support a variety of communication services, as with many features and applications of the transmission network, and we must adapt to the trend of development, and actively track the development of new technologies to expand the network of clients, improve network construction and management, to maximize the play to the network edge. entries Atlas Atlas

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References 1

digital data DDN data reference.

digital data DDN

2

DDN definitions, principles and characteristics

http://hi.baidu.com/yoyx/blog/item/0a6c20c8f31d29107e3e6f2e.html

Further reading: 1

DDN standard digital data rates: http://www.9orange.com/dxgnddn/

2

http://www.tangmat.com/ddn.php

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