布线
作者：anlph 发布时间：2008-04-11 19:02:00 浏览次数：513
什么是网络布线？
Cable is the medium through which information usually moves from one network device to another.电缆是中等通过这些信息通常是从一个网络设备到另一个地方。 There are several types of cable which are commonly used with LANs.有多种类型的电缆，这是常用的局域网。 In some cases, a network will utilize only one type of cable, other networks will use a variety of cable types.在某些情况下，网络将利用中只有一个型号的电缆，其他网络将利用各种电缆类型。 The type of cable chosen for a network is related to the network's topology, protocol, and size.该类型的电缆选择一个网络，是关系到网络的拓扑结构，协议和大小。 Understanding the characteristics of different types of cable and how they relate to other aspects of a network is necessary for the development of a successful network.了解的特点，不同类型的电缆，以及他们如何与其他方面的一个网络，是发展所必需的一个成功的网络。
The following sections discuss the types of cables used in networks and other related topics.以下各节讨论类型的电缆，用于在网络和其他相关主题。
- Unshielded Twisted Pair (UTP) Cable 非屏蔽双绞线（ UTP线缆）电缆
- Shielded Twisted Pair (STP) Cable 屏蔽双绞线（污水处理厂）电缆
- Coaxial Cable 同轴电缆
- Fiber Optic Cable 光纤电缆
- Wireless LANs 无线局域网
- Cable Installation Guides 有线电视安装指南
Unshielded Twisted Pair (UTP) Cable非屏蔽双绞线（ UTP线缆）电缆
Twisted pair cabling comes in two varieties: shielded and unshielded.双绞线布线播放器有两种不同的版本：屏蔽和非屏蔽。 Unshielded twisted pair (UTP) is the most popular and is generally the best option for school networks (See fig. 1).非屏蔽双绞线（ UTP布线） ，是目前最流行的，而且一般是最佳的选择，为学校网络（见图1 ） 。
Fig.1. 图1 。 Unshielded twisted pair 非屏蔽双绞线
The quality of UTP may vary from telephone-grade wire to extremely high-speed cable.质量的UTP可能会有所变动，从电话级导线，以极高的高速电缆。 The cable has four pairs of wires inside the jacket.有线电视已4双内的电线外皮。 Each pair is twisted with a different number of twists per inch to help eliminate interference from adjacent pairs and other electrical devices.每一组的是扭曲与不同数量的波折，每英寸，以帮助排除干扰，从相邻配对及其他电器设备。 The tighter the twisting, the higher the supported transmission rate and the greater the cost per foot.越窄，捻线，上级支持的传输速率和更大的成本每英尺。 The EIA/TIA (Electronic Industry Association/Telecommunication Industry Association) has established standards of UTP and rated five categories of wire.环评/电信行业协会（电子工业协会/电信工业协会）已经设立标准的UTP和额定五类线。
Categories of Unshielded Twisted Pair类非屏蔽双绞线
|
Buy the best cable you can afford; most schools purchase Category 3 or Category 5.购买最好的电缆，你可以负担得起;大多数学校购买3类或第5类。 If you are designing a 10 Mbps Ethernet network and are considering the cost savings of buying Category 3 wire instead of Category 5, remember that the Category 5 cable will provide more "room to grow" as transmission technologies increase.如果你正在设计一个10 Mbps以太网网络，并考虑到节省成本，购买第三类丝代替第5类，记得当时第5类电缆，会提供更多的"成长空间"作为传输技术提高了。 Both Category 3 and Category 5 UTP have a maximum segment length of 100 meters.双方第3类和第5类的UTP有一个最大段长度为100米。 In Florida, Category 5 cable is required for retrofit grants.在佛罗里达州，第5类电缆是需要改造赠款。 10BaseT refers to the specifications for unshielded twisted pair cable (Category 3, 4, or 5) carrying Ethernet signals. 10baset是指以规范非屏蔽双绞线电缆（ 3类， 4或5 ）进行以太网信号。 Category 6 is relatively new and is used for gigabit connections.第6类是比较新的，是用来为千兆连接。
Unshielded Twisted Pair Connector非屏蔽双绞线连接器
The standard connector for unshielded twisted pair cabling is an RJ-45 connector.标准连接器非屏蔽双绞线布线是一个RJ - 45接头。 This is a plastic connector that looks like a large telephone-style connector (See fig. 2).这是一个塑料连接器看上去像一个大型的电话式连接器（见图2 ） 。 A slot allows the RJ-45 to be inserted only one way.插槽允许的RJ - 45至插入出路只有一条。 RJ stands for Registered Jack, implying that the connector follows a standard borrowed from the telephone industry.的RJ主张注册杰克，这意味着该连接器如下标准借来的，由电话业。 This standard designates which wire goes with each pin inside the connector.这个标准指定其中线材，顺每个管脚内的连接器。
Fig. 图。 2. 2 。 RJ-45 connector RJ - 45接头
Shielded Twisted Pair (STP) Cable屏蔽双绞线（污水处理厂）电缆
A disadvantage of UTP is that it may be susceptible to radio and electrical frequency interference.处于不利地位的UTP是，它可能受到电台和电频率干扰。 Shielded twisted pair (STP) is suitable for environments with electrical interference; however, the extra shielding can make the cables quite bulky.屏蔽双绞线（污水处理厂） ，是适合的环境与电波干扰;然而，这笔额外的屏蔽，可以使电缆相当笨重。 Shielded twisted pair is often used on networks using Token Ring topology.屏蔽双绞线通常被用来对网络使用令牌环拓扑。
Coaxial Cable同轴电缆
Coaxial cabling has a single copper conductor at its center.同轴线缆有一个单一的铜导线，在它的中心。 A plastic layer provides insulation between the center conductor and a braided metal shield (See fig. 3).一个塑料层提供绝缘之间的中心导体和编织金属屏蔽（见图3 ） 。 The metal shield helps to block any outside interference from fluorescent lights, motors, and other computers.金属屏蔽有助于阻止任何外界干扰，荧光灯，电机，和其它计算机。
Fig. 图。 3. 3 。 Coaxial cable 同轴电缆
Although coaxial cabling is difficult to install, it is highly resistant to signal interference.虽然同轴布线很难安装，它是高抗信号干扰。 In addition, it can support greater cable lengths between network devices than twisted pair cable.此外，它可以支持更大的电缆长度之间的网络设备比双绞线电缆。 The two types of coaxial cabling are thick coaxial and thin coaxial.这两个类型的同轴电缆布线厚同轴和细同轴。
Thin coaxial cable is also referred to as thinnet.细同轴电缆也被称为thinnet 。 10Base2 refers to the specifications for thin coaxial cable carrying Ethernet signals. 10base2是指以规格薄同轴电缆进行以太网信号。 The 2 refers to the approximate maximum segment length being 200 meters.二是指以最高约段长度正在200米。 In actual fact the maximum segment length is 185 meters.实际上，最大段长度185米。 Thin coaxial cable is popular in school networks, especially linear bus networks.细同轴电缆是流行在校园网络中，特别是线性总线网络。
Thick coaxial cable is also referred to as thicknet.粗同轴电缆，也被称为thicknet 。 10Base5 refers to the specifications for thick coaxial cable carrying Ethernet signals. 10base5是指以规格为厚同轴电缆进行以太网信号。 The 5 refers to the maximum segment length being 500 meters.五是指以最高段长度500米。 Thick coaxial cable has an extra protective plastic cover that helps keep moisture away from the center conductor.厚厚的同轴电缆有一个额外的保护塑料罩，有利于保持水分远离中心的指挥家。 This makes thick coaxial a great choice when running longer lengths in a linear bus network.这使得厚同轴一种伟大的选择，当运行较长篇幅的线性总线网络。 One disadvantage of thick coaxial is that it does not bend easily and is difficult to install.一个不利的厚同轴的是，它没有弯曲，很容易而且很难安装。
Coaxial Cable Connectors同轴电缆连接器
The most common type of connector used with coaxial cables is the Bayone-Neill-Concelman (BNC) connector (See fig. 4).最常见的连接器用来与同轴电缆是bayone -尼尔- concelman （电流） ，连接器（见图4 ） 。 Different types of adapters are available for BNC connectors, including a T-connector, barrel connector, and terminator.不同类型的适配器，以供BNC连接器，其中包括T型连接器，桶接头，并终结者。 Connectors on the cable are the weakest points in any network.连接器对有线电视是最薄弱点，在任何网络。 To help avoid problems with your network, always use the BNC connectors that crimp, rather than screw, onto the cable.有助于避免问题，你的网络，始终用BNC连接器即卷曲，而不是螺丝钉，把电缆。
Fig. 图。 4. 4 。 BNC connector 高电流连接器
Fiber Optic Cable光纤电缆
Fiber optic cabling consists of a center glass core surrounded by several layers of protective materials (See fig. 5).光纤线缆包括一个中心玻璃核心包围数层防护材料（见图5 ） 。 It transmits light rather than electronic signals eliminating the problem of electrical interference.它传达了光，而不是电子信号，消除问题的电波干扰。 This makes it ideal for certain environments that contain a large amount of electrical interference.这就使他的理想一定的环境中含有大量的电子干扰。 It has also made it the standard for connecting networks between buildings, due to its immunity to the effects of moisture and lighting.它也使得它的标准，用于连接网络之间的建筑物，由于其自身免疫能力的影响，湿度和照明设施。
Fiber optic cable has the ability to transmit signals over much longer distances than coaxial and twisted pair.海底光缆有能力传送信号，超过更长的距离比同轴电缆和双绞线。 It also has the capability to carry information at vastly greater speeds.它也有能力进行信息在大大加快。 This capacity broadens communication possibilities to include services such as video conferencing and interactive services.这方面的容量扩大了沟通的可能性，包括服务，如视频会议及交互式服务。 The cost of fiber optic cabling is comparable to copper cabling; however, it is more difficult to install and modify.成本的光纤电缆是可比铜布线，但它是更加困难的安装和修改的。 10BaseF refers to the specifications for fiber optic cable carrying Ethernet signals. 10basef指以规格为光纤电缆进行以太网信号。
Fig.5. 图5 。 Fiber optic cable 光纤电缆
Facts about fiber optic cables:事实光纤电缆：
- Outer insulating jacket is made of Teflon or PVC.外层绝缘护套了特氟隆或PVC 。
- Kevlar fiber helps to strengthen the cable and prevent breakage.芳纶纤维有助于增强有线和防止破损。
- A plastic coating is used to cushion the fiber center.一个塑料涂层是用来垫纤维中心。
- Center (core) is made of glass or plastic fibers.中心（核心）是由玻璃或塑料纤维。
Fiber Optic Connector光纤连接器
The most common connector used with fiber optic cable is an ST connector.最常见的连接器使用的光纤电缆，是圣连接器。 It is barrel shaped, similar to a BNC connector.这是每桶形，类似于一个高电流连接器。 A newer connector, the SC, is becoming more popular.一个新的连接器，资深大律师，是越来越受欢迎。 It has a squared face and is easier to connect in a confined space.它有一个方面，是比较容易连接在一个密闭空间。
Ethernet Cable Summary以太网电缆综述
|
Wireless LANs无线局域网
Not all networks are connected with cabling; some networks are wireless.并非所有的网络连接与布线;一些网络是无线。 Wireless LANs use high frequency radio signals, infrared light beams, or lasers to communicate between the workstations and the file server or hubs.无线局域网使用的高频率无线电信号，红外光束，或激光器之间进行通信的工作站和文件服务器或集线器。 Each workstation and file server on a wireless network has some sort of transceiver/antenna to send and receive the data.每个工作站和文件服务器上一个无线网络已经以某种收发器/天线来传送和接收数据。 Information is relayed between transceivers as if they were physically connected.信息传达之间收发器，因为如果他们身体连接。 For longer distance, wireless communications can also take place through cellular telephone technology, microwave transmission, or by satellite.作较长时间的距离，无线通讯也可以通过移动电话技术，微波传输，或由卫星。
Wireless networks are great for allowing laptop computers or remote computers to connect to the LAN.无线网络是伟大，让笔记型电脑或远程计算机连接到网络。 Wireless networks are also beneficial in older buildings where it may be difficult or impossible to install cables.无线网络，同时也有利于在较旧的建筑物，可能很难或根本不可能安装电缆。
The two most common types of infrared communications used in schools are line-of-sight and scattered broadcast.两种最常见的红外通信用在学校的瞄准线与分散相播出。 Line-of-sight communication means that there must be an unblocked direct line between the workstation and the transceiver.瞄准线通信手段，即必须有一个畅通的直接线之间的工作站和收发器。 If a person walks within the line-of-sight while there is a transmission, the information would need to be sent again.如果一个人阶层内部的瞄准线，而有一个传输，信息需要被派到了。 This kind of obstruction can slow down the wireless network.这种阻塞，可以放慢无线网络。
Scattered infrared communication is a broadcast of infrared transmissions sent out in multiple directions that bounces off walls and ceilings until it eventually hits the receiver.分散红外通信是一个播出的红外线传送派出多个方向反弹墙壁和天花板上，直到最后击中接收器。 Networking communications with laser are virtually the same as line-of-sight infrared networks.网络通信与激光几乎是一样的瞄准线红外网络。
Wireless LANs have several disadvantages.无线局域网有几个缺点。 They provide poor security, and are susceptible to interference from lights and electronic devices.他们穷人提供安全，而且也容易受到干扰，从灯光和电子设备等。 They are also slower than LANs using cabling.他们也慢于使用局域网布线。
Installing Cable - Some Guidelines安装电缆-一些指引
When running cable, it is best to follow a few simple rules:当运行电缆，最好是遵循一些简单的规则：
- Always use more cable than you need.总是用更多的电缆比你所需要的人。 Leave plenty of slack.离开大量的疲弱。
- Test every part of a network as you install it.测试每一个网络的一部分，正如你安装它。 Even if it is brand new, it may have problems that will be difficult to isolate later.即使是全新的，它可能有问题，这将是困难的，孤立的。
- Stay at least 3 feet away from fluorescent light boxes and other sources of electrical interference.留至少3英尺远从荧光灯灯箱和其他来源的电子干扰。
- If it is necessary to run cable across the floor, cover the cable with cable protectors.如果是必须运行电缆地板，涵盖了有线与有线电视的保护者。
- Label both ends of each cable.标签两端各电缆。
- Use cable ties (not tape) to keep cables in the same location together.利用有线电视的关系（而不是磁带） ，使电缆在同一地点一起。
