DDN network has made great contributions to the development of Private Line Service.
DDN网络为专线业务的发展做出了较大的贡献，但是，其网络的持续发展却遇到了诸多困难。
Decoration StandardsMetal ceilings, grid lamps, wind port louver, smoke detectors, sprinklers, 75mm high elevated platform meshwork floor, carpet, wall with timber skirting and emulsion paintElevators14 Schindler passenger elevators, among which, 5 for the lower zone, 5 for the middle zone and 4 for the higher zone, and 2 Schindler fire elevatorsAir conditioning SystemUS TRANE central air conditioning system with a total cooling capacity of not less than 3500TR and fresh air volume of 50 cubic meter per hourElectricity SystemThe total electricity capacity is not less than 7500kV, the power supply capacity per square meter in the office area is not less than 0.17kV, and indoor illumination standard is not lower than 50 luxCommunication SystemThere are not less than 200 telephone lines for each floor.
装修标准金属天花吊顶，格栅灯、风口百页、烟感、喷洒器、75mm高架网络地板、地毯、木脚线墙面、乳胶漆电梯14部进口Schindler乘客电梯，低区：5部、中区：5部、高区：4部，2部进口Schindler消防电梯空调系统美国特灵牌中央空调系统，总制冷量不小于3500冷吨，新风量：50立方米/小时电力系统总供电容量不小于7500千伏，办公区内每平米供电量不少于0.17千伏，室内照明标准不少于500lux通讯系统每层不少于200根电话直线，每层提供光纤干管和通讯设备，方便ISDN、ADSL、DDN宽带系统接入标准地板承载量300公斤/平方米
Around it there are New Baiyun Airport, Jing-Guang Railway, No.105, 106, and 107 national highways and many expressways. No.3 and No.9 underground lines also pass by our base. We provide consummate service for every customer, e. g. provide 200 thousand cubic meters of water for industry and living per day, 4*4000kva electricity supply, and communication network, IDD telephone, ADSL, LAN, and all different kinds of telecom services.
产业基地所处位置，交通网络十分发达，周边有广州白云国际机场，京广铁路，武广铁路客运快线，105，106，107国道以及京珠，机场，广清，街北高速公路，有规划中的轻轨交通3号，9号线，产业基地的各项配套齐备，供水日供20万方/日，供电10千伏线供电，可供4×4000KVA，通讯，网络可随时提供IDD 控电话，ADSL，LAN等宽带接入及DDN等各项电信业务。
Rhodamine B, Malachite green, Auramine O, Bismark Brown, Methyl Violet 5BN, Basic Magenta, Acid Orange II, Chrysophenine GX, Direct Fast Black G, Indigo, Sulphur Black, Solvent Red 24, Solvent Red 49, Solvent Brown 41, Solvent Orange 3, Pigment Yellow 154, 155, Pigment Red 188, 208, Meta-Diethyiaminophenol, M-Amino acetanilide, P-Amino acetanilide, etc.
主要产品：碱性玫瑰精，碱性品绿，碱性嫩黄O，碱性品红，碱性紫5BN，碱性红6DDN，酸性橙II，靛蓝，硫化黑，直接冻黄，直接黑G，溶剂红24，溶剂红49，溶剂棕41，溶剂橙3，溶剂橙62，颜料黄154，155，颜料红188，208，间羟基－N，N－二乙基苯胺，间氨基乙酰苯胺，对氨基乙酰苯胺。
This system introduced a three-gradation structure, that is, supervision module, supervision unit and supervision center; adopted the existing 97 network and PSTN network, E1 as the main transport channel and DDN as the spare transport channel.
本监控系统采用三级分层结构，即前置监控单元、局站监控中心和区域监控中心；系统组网利用现有的97网和PSTN网，主传输通道为E1，备用通道为DDN；SM与SU之间采用RS-485/422、RS-232等现场总线进行连接。
The new way not only lowered the cost of investment and application but also ensured the speed and quality of DDN data transmission.
这种接入方式降低了投入和应用的成本，又保证了ddn专线数据传输的速率和质量。
This is used for all kinds of experiments, including network foundation, organization of network, Web/FTP service and computer network communication. Cell switch, frame relay, DDN, and ATM are included in these experiments.
实验室可用于网络基础、组网、WebFTP服务、计算机网络通讯等多种实验，包括DDN、ATM、信元交换、帧中继交换等。
Application of DDN in Guangdong Digital Telemetry Seismographic Network
数字通信网络在广东数字地震遥测台网中的应用
Two typical cases are discussed: network connected with Modem and dial, or network connected with router and DDN. A detail method of internetworking is given for you.
文中给出了用电话线通过Modem进行网络连接和用DDN线路通过路由器进行网络连接两种方案，重点讨论了异网互连的数据传输问题，并提供了一种具体的实现方法。
A DDN trunk channel is interrupted much more frequently in mobile telecommunications than one in fixed telecommunications. Therefore, interrupting time of DDN equipment becomes more important in mobile telecommunications, which makes the availability of a DDN circuit much poorer than that of a DDN trunk channel.
在无线移动场合下，DDN中继信道的中断比固定场合下频繁得多，DDN设备中断恢复时间长的问题就变得突出起来，这使得DDN电路的可用性远小于DDN中继信道的可用性。
Reducing DDN Interrupting Time
减少DDN设备中断恢复时间的探讨
Adopted the existing 97 network and PSTN network, El as the main transport channel and DDN as the spare transport channel.
系统组网利用现有的97网和PSTN网，主传输通道为E1，备用通道为DDN；
Traditional DDN Private Network belongs to star topology with shortcomings of difficult adjustment of logical topology and worse extendibility and maintainability of network.
传统DDN专网属于星型拓扑结构，缺点是逻辑拓扑难于调整、网络可扩展性和可维护性较差。
Long-distance network way through WAN by DDN, X.25, ISDN, and the communication by 2M the El line in the meantime, are supported. Under this way, pronunciation and image may be transmitted simultaneously.
系统的组网方式非常灵活，系统支持通过DDN、X.25、ISDN等广域网进行的远距离组网方式、同时也支持2M的E1线路进行通讯，在这种方式下，可同时传递语音和图像。
A digital data network (DDN) is a data transmission network within which digital channels are utilized for data signal transmission.
数字数据网（DDN）是采用数字信道来传输数据信号的数据传输网。数据通信技术中，一种宽频带的信道。
Remote Hospital Network Management: Rational Use of Vpn and Ddn
医院异地网络通信管理&合理运用vpn和ddn数字专线
Overall Consideration for the Development of DDN in China
发展我国数字数据网的总体技术设想
Ddn't I say the bus broke down?
我不是说过车坏了吗？
I wasn't there, therefore I ddn't see.
我不在那儿，所以没有看见。
I ddn't know t was you, piease forgve me.
我不知道是你，请原谅。