通信人家园
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[转帖]认识光端机与光猫的区别
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时间:
2007-3-16 14:45
作者:
wanglh1211
标题:
[转帖]认识光端机与光猫的区别
<p style="LINE-HEIGHT: 150%;"><span style="FONT-SIZE: 10pt; mso-ascii-font-family: "\000B _GB2312"; mso-hansi-font-family: "\000B _GB2312";">光猫是一种类似于基带</span><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;">MODEM</span><span style="FONT-SIZE: 10pt; mso-ascii-font-family: "\000B _GB2312"; mso-hansi-font-family: "\000B _GB2312";">（数字调制解调器）的设备，和基带</span><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;">MODEM</span><span style="FONT-SIZE: 10pt; mso-ascii-font-family: "\000B _GB2312"; mso-hansi-font-family: "\000B _GB2312";">不同的是接入的是光纤专线，是光信号。</span><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;"><p></p></span></p><p style="LINE-HEIGHT: 150%;"><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;"> </span><span style="FONT-SIZE: 10pt; mso-ascii-font-family: "\000B _GB2312"; mso-hansi-font-family: "\000B _GB2312";">用于广域网中光电信号的转换和接口协议的转换，接入路由器，是广域网接入。光电收发器是用局域网中光电信号的转换，而仅仅是信号转换，没有接口协议的转换。一般用在园区网内较长距离，不适于布双绞线的环境。为了说清楚光猫、光电收发器。我们有必要介绍它们所运用的环境。</span><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;"><p></p></span></p><p style="LINE-HEIGHT: 150%;"><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;"> </span><span style="FONT-SIZE: 10pt; mso-ascii-font-family: "\000B _GB2312"; mso-hansi-font-family: "\000B _GB2312";">光</span><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;">Modem</span><span style="FONT-SIZE: 10pt; mso-ascii-font-family: "\000B _GB2312"; mso-hansi-font-family: "\000B _GB2312";">也称为单端口光端机，是针对特殊用户环境而设计的产品，它利用一对光纤进行单</span><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;">E1</span><span style="FONT-SIZE: 10pt; mso-ascii-font-family: "\000B _GB2312"; mso-hansi-font-family: "\000B _GB2312";">或单</span><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;">V.35</span><span style="FONT-SIZE: 10pt; mso-ascii-font-family: "\000B _GB2312"; mso-hansi-font-family: "\000B _GB2312";">或单</span><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;">10BaseT</span><span style="FONT-SIZE: 10pt; mso-ascii-font-family: "\000B _GB2312"; mso-hansi-font-family: "\000B _GB2312";">点到点式的光传输终端设备。该设备作为本地网的中继传输设备，适用于基站的光纤终端传输设备以及租用线路设备。而对于多口的光端机一般会直称作“光端机”，对单端口光端机一般使用于用户端，工作类似常用的广域网专线（电路）联网用的基带</span><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;">MODEM</span><span style="FONT-SIZE: 10pt; mso-ascii-font-family: "\000B _GB2312"; mso-hansi-font-family: "\000B _GB2312";">，而有称作“光</span><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;">MODEM</span><span style="FONT-SIZE: 10pt; mso-ascii-font-family: "\000B _GB2312"; mso-hansi-font-family: "\000B _GB2312";">”、“光猫”、“光调制解调器”。</span><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;"><p></p></span></p><p style="LINE-HEIGHT: 150%;"><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;"> </span><span style="FONT-SIZE: 10pt; mso-ascii-font-family: "\000B _GB2312"; mso-hansi-font-family: "\000B _GB2312";">在这里我举一个产品的例子：广州华信通信设备有限公司生产的</span><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;">HS-OPT122 V.35</span><span style="FONT-SIZE: 10pt; mso-ascii-font-family: "\000B _GB2312"; mso-hansi-font-family: "\000B _GB2312";">光端机</span><span style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;">
</span><span style="FONT-SIZE: 10pt; mso-ascii-font-family: "\000B _GB2312"; mso-hansi-font-family: "\000B _GB2312";">（见图</span><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;">1</span><span style="FONT-SIZE: 10pt; mso-ascii-font-family: "\000B _GB2312"; mso-hansi-font-family: "\000B _GB2312";">），该设备提供了</span><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;">1</span><span style="FONT-SIZE: 10pt; mso-ascii-font-family: "\000B _GB2312"; mso-hansi-font-family: "\000B _GB2312";">路</span><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;">V.35</span><span style="FONT-SIZE: 10pt; mso-ascii-font-family: "\000B _GB2312"; mso-hansi-font-family: "\000B _GB2312";">数据通道，此接口可接入路由器的</span><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;">V.35</span><span style="FONT-SIZE: 10pt; mso-ascii-font-family: "\000B _GB2312"; mso-hansi-font-family: "\000B _GB2312";">数据接口。光端机的</span><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;">E1</span><span style="FONT-SIZE: 10pt; mso-ascii-font-family: "\000B _GB2312"; mso-hansi-font-family: "\000B _GB2312";">和</span><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;">V.35</span><span style="FONT-SIZE: 10pt; mso-ascii-font-family: "\000B _GB2312"; mso-hansi-font-family: "\000B _GB2312";">接口速率都可通过拨码开关任意调节，可透传</span><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;">2M</span><span style="FONT-SIZE: 10pt; mso-ascii-font-family: "\000B _GB2312"; mso-hansi-font-family: "\000B _GB2312";">数据。</span><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;">HS-OPT122 V.35</span><span style="FONT-SIZE: 10pt; mso-ascii-font-family: "\000B _GB2312"; mso-hansi-font-family: "\000B _GB2312";">光端机可作为本地网的中继传输设备</span><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;">,</span><span style="FONT-SIZE: 10pt; mso-ascii-font-family: "\000B _GB2312"; mso-hansi-font-family: "\000B _GB2312";">尤其适合作为移动通信网基站的光纤终端传输设备以及租用设备。</span><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;"><p></p></span></p><p style="LINE-HEIGHT: 150%;"><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;"> </span><span style="FONT-SIZE: 10pt; mso-ascii-font-family: "\000B _GB2312"; mso-hansi-font-family: "\000B _GB2312";">我这里所指的光端机仅仅是在数据通信上的产品，实际光端机的产品五花八门，有用有线电视传输的，有用于电话传输的，有用工业控制的，有的甚至是集“语音、数据、图像”等业务接入于一体，如：西门子</span><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;"> OLTE8</span><span style="FONT-SIZE: 10pt; mso-ascii-font-family: "\000B _GB2312"; mso-hansi-font-family: "\000B _GB2312";">型</span><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;">4E1</span><span style="FONT-SIZE: 10pt; mso-ascii-font-family: "\000B _GB2312"; mso-hansi-font-family: "\000B _GB2312";">光端机（见图</span><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;">2</span><span style="FONT-SIZE: 10pt; mso-ascii-font-family: "\000B _GB2312"; mso-hansi-font-family: "\000B _GB2312";">）</span><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;"><p></p></span></p><p style="LINE-HEIGHT: 150%;"><span style="FONT-SIZE: 10pt; mso-ascii-font-family: "\000B _GB2312"; mso-hansi-font-family: "\000B _GB2312";">光纤收发器在以太网中实现单、多模光纤与双绞线之间的信号转换。光纤收发器是一种将短距离的双绞线电信号和长距离的光信号进行互换的以太网传输媒体转换单元。光纤收发器一般应用在以太网电缆无法覆盖、必须使用光纤来延长传输距离的实际网络环境中；同时在帮助把光纤最后一公里线路连接到城域网（属于以太网技术）和更外层的网络上也发挥了巨大的作用。</span><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;"><p></p></span></p><p style="LINE-HEIGHT: 150%;"><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;"> </span><span style="FONT-SIZE: 10pt; mso-ascii-font-family: "\000B _GB2312"; mso-hansi-font-family: "\000B _GB2312";">按速率来分，光纤收发器可以分为单</span><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;">10M</span><span style="FONT-SIZE: 10pt; mso-ascii-font-family: "\000B _GB2312"; mso-hansi-font-family: "\000B _GB2312";">、</span><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;">100M</span><span style="FONT-SIZE: 10pt; mso-ascii-font-family: "\000B _GB2312"; mso-hansi-font-family: "\000B _GB2312";">的光纤收发器、</span><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;">10/100M</span><span style="FONT-SIZE: 10pt; mso-ascii-font-family: "\000B _GB2312"; mso-hansi-font-family: "\000B _GB2312";">自适应的光纤收发器和</span><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;">1000M</span><span style="FONT-SIZE: 10pt; mso-ascii-font-family: "\000B _GB2312"; mso-hansi-font-family: "\000B _GB2312";">光纤收发器。</span><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;">10M</span><span style="FONT-SIZE: 10pt; mso-ascii-font-family: "\000B _GB2312"; mso-hansi-font-family: "\000B _GB2312";">和</span><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;">100M</span><span style="FONT-SIZE: 10pt; mso-ascii-font-family: "\000B _GB2312"; mso-hansi-font-family: "\000B _GB2312";">的收发器工作在物理层，在这一层工作的收发器产品是按位来转发数据。该转发方式具有转发速度快、通透率高、时延低等方面的优势，在兼容性和稳定性方面较好，适合应用于速率固定的链路上。</span><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;"><p></p></span></p><p style="LINE-HEIGHT: 150%;"><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;"> </span><span style="FONT-SIZE: 10pt; mso-ascii-font-family: "\000B _GB2312"; mso-hansi-font-family: "\000B _GB2312";">而</span><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;">10/100M</span><span style="FONT-SIZE: 10pt; mso-ascii-font-family: "\000B _GB2312"; mso-hansi-font-family: "\000B _GB2312";">光纤收发器是工作在数据链路层，在这一层光纤收发器使用存储转发的机制，对接收到的每一个数据包都要读取它的源</span><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;">MAC</span><span style="FONT-SIZE: 10pt; mso-ascii-font-family: "\000B _GB2312"; mso-hansi-font-family: "\000B _GB2312";">地址、目的</span><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;">MAC</span><span style="FONT-SIZE: 10pt; mso-ascii-font-family: "\000B _GB2312"; mso-hansi-font-family: "\000B _GB2312";">地址和数据，在完成</span><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;">CRC</span><span style="FONT-SIZE: 10pt; mso-ascii-font-family: "\000B _GB2312"; mso-hansi-font-family: "\000B _GB2312";">循环冗余校验以后才将该数据包转发出去。一来可以防止一些错误的帧在网络中传播，占用宝贵的网络资源，同时还可以很好地防止由于网络拥塞造成的数据包丢失。</span><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;"><p></p></span></p><p style="LINE-HEIGHT: 150%;"><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;"> </span><span style="FONT-SIZE: 10pt; mso-ascii-font-family: "\000B _GB2312"; mso-hansi-font-family: "\000B _GB2312";">按结构来分，可以分为桌面式光纤收发器和机架式光纤收发器。桌面式光纤收发器适合于单个用户使用，如满足楼道中单台交换机的上联。机架式光纤收发器适用于多用户的汇聚。</span><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;"><p></p></span></p><p style="LINE-HEIGHT: 150%;"><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;"> </span><span style="FONT-SIZE: 10pt; mso-ascii-font-family: "\000B _GB2312"; mso-hansi-font-family: "\000B _GB2312";">按光纤来分，可以分为多模光纤收发器和单模光纤收发器。由于使用的光纤不同，收发器所能传输的距离也不一样，多模收发器一般的传输距离在</span><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;">2</span><span style="FONT-SIZE: 10pt; mso-ascii-font-family: "\000B _GB2312"; mso-hansi-font-family: "\000B _GB2312";">公里到</span><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;">5</span><span style="FONT-SIZE: 10pt; mso-ascii-font-family: "\000B _GB2312"; mso-hansi-font-family: "\000B _GB2312";">公里之间，而单模收发器覆盖的范围可以从</span><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;">20</span><span style="FONT-SIZE: 10pt; mso-ascii-font-family: "\000B _GB2312"; mso-hansi-font-family: "\000B _GB2312";">公里至</span><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;">120</span><span style="FONT-SIZE: 10pt; mso-ascii-font-family: "\000B _GB2312"; mso-hansi-font-family: "\000B _GB2312";">公里。需要指出的是因传输距离的不同，光纤收发器本身的发射功率、接收灵敏度和使用波长也会不一样。</span><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;">5</span><span style="FONT-SIZE: 10pt; mso-ascii-font-family: "\000B _GB2312"; mso-hansi-font-family: "\000B _GB2312";">公里光纤收发器的发射功率一般在</span><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;">-20</span><span style="FONT-SIZE: 10pt; mso-ascii-font-family: "\000B _GB2312"; mso-hansi-font-family: "\000B _GB2312";">～</span><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;">-14db</span><span style="FONT-SIZE: 10pt; mso-ascii-font-family: "\000B _GB2312"; mso-hansi-font-family: "\000B _GB2312";">之间，接收灵敏度为</span><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;">-30db</span><span style="FONT-SIZE: 10pt; mso-ascii-font-family: "\000B _GB2312"; mso-hansi-font-family: "\000B _GB2312";">，使用</span><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;">1310nm</span><span style="FONT-SIZE: 10pt; mso-ascii-font-family: "\000B _GB2312"; mso-hansi-font-family: "\000B _GB2312";">的波长；而</span><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;">120</span><span style="FONT-SIZE: 10pt; mso-ascii-font-family: "\000B _GB2312"; mso-hansi-font-family: "\000B _GB2312";">公里光纤收发器的发射功率多在</span><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;">-5</span><span style="FONT-SIZE: 10pt; mso-ascii-font-family: "\000B _GB2312"; mso-hansi-font-family: "\000B _GB2312";">～</span><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;">0dB</span><span style="FONT-SIZE: 10pt; mso-ascii-font-family: "\000B _GB2312"; mso-hansi-font-family: "\000B _GB2312";">之间，接收灵敏度为</span><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;">-38dB</span><span style="FONT-SIZE: 10pt; mso-ascii-font-family: "\000B _GB2312"; mso-hansi-font-family: "\000B _GB2312";">，使用</span><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;">1550nm</span><span style="FONT-SIZE: 10pt; mso-ascii-font-family: "\000B _GB2312"; mso-hansi-font-family: "\000B _GB2312";">的波长。</span><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;"><p></p></span></p><p style="LINE-HEIGHT: 150%;"><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;"> </span><span style="FONT-SIZE: 10pt; mso-ascii-font-family: "\000B _GB2312"; mso-hansi-font-family: "\000B _GB2312";">按光纤数量来分，可以分为单纤光纤收发器和双纤光纤收发器。单纤是在一根光纤上实现数据的接收和发送，这类产品采用了波分复用的技术，使用的波长多为</span><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;">1310nm</span><span style="FONT-SIZE: 10pt; mso-ascii-font-family: "\000B _GB2312"; mso-hansi-font-family: "\000B _GB2312";">和</span><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;">1550nm</span><span style="FONT-SIZE: 10pt; mso-ascii-font-family: "\000B _GB2312"; mso-hansi-font-family: "\000B _GB2312";">。由于使用了波分复用，单纤收发器产品普遍存在信号衰耗大的特点。目前市面上的光纤收发器多为双纤产品，此类产品较为成熟和稳定。</span><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;"><p></p></span></p><p style="LINE-HEIGHT: 150%;"><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;"> </span><span style="FONT-SIZE: 10pt; mso-ascii-font-family: "\000B _GB2312"; mso-hansi-font-family: "\000B _GB2312";">同样我们也举一个光纤收发器的例子：</span><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;">NETCORE</span><span style="FONT-SIZE: 10pt; mso-ascii-font-family: "\000B _GB2312"; mso-hansi-font-family: "\000B _GB2312";">中国有限公司生产的</span><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;">4240NF</span><span style="FONT-SIZE: 10pt; mso-ascii-font-family: "\000B _GB2312"; mso-hansi-font-family: "\000B _GB2312";">系列光纤收发器（见图</span><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;">4</span><span style="FONT-SIZE: 10pt; mso-ascii-font-family: "\000B _GB2312"; mso-hansi-font-family: "\000B _GB2312";">）</span><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;"><p></p></span></p><p align="center" style="LINE-HEIGHT: 150%; TEXT-ALIGN: center;"><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;"> <p></p></span></p><p style="LINE-HEIGHT: 150%;"><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;"> </span><strong><span style="COLOR: red; FONT-SIZE: 10pt; mso-ascii-font-family: "\000B _GB2312"; mso-hansi-font-family: "\000B _GB2312";">问题</span></strong><strong><span lang="EN-US" style="COLOR: red; FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;">2</span></strong><strong><span style="COLOR: red; FONT-SIZE: 10pt; mso-ascii-font-family: "\000B _GB2312"; mso-hansi-font-family: "\000B _GB2312";">：</span></strong><span style="FONT-SIZE: 10pt; mso-ascii-font-family: "\000B _GB2312"; mso-hansi-font-family: "\000B _GB2312";">我经常看到有些网吧写着百兆光纤接入，千兆接入，怎么回事？谁给解释一下？</span><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt;"><p></p></span></p><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt; mso-fareast-font-family: 宋体; mso-bidi-font-family: "Times New Roman"; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA;"> </span><span style="FONT-FAMILY: 宋体; FONT-SIZE: 10pt; mso-ascii-font-family: "\000B _GB2312"; mso-hansi-font-family: "\000B _GB2312"; mso-bidi-font-family: "Times New Roman"; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA;">这些光纤接入实际上只是到网络运营商放置在网吧所在地附近的它自己的交换机这段的百兆光纤接入，千兆接入。（网吧若这样宣传有欺诈网友之嫌）实际上还有最后一公里的问题，就是从这台交换机到营运商电信机房这段是属于城域网的范围，可能是</span><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt; mso-fareast-font-family: 宋体; mso-bidi-font-family: "Times New Roman"; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA;">1M</span><span style="FONT-FAMILY: 宋体; FONT-SIZE: 10pt; mso-ascii-font-family: "\000B _GB2312"; mso-hansi-font-family: "\000B _GB2312"; mso-bidi-font-family: "Times New Roman"; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA;">，</span><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt; mso-fareast-font-family: 宋体; mso-bidi-font-family: "Times New Roman"; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA;">2M</span><span style="FONT-FAMILY: 宋体; FONT-SIZE: 10pt; mso-ascii-font-family: "\000B _GB2312"; mso-hansi-font-family: "\000B _GB2312"; mso-bidi-font-family: "Times New Roman"; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA;">，最多</span><span lang="EN-US" style="FONT-FAMILY: "\000B _GB2312"; FONT-SIZE: 10pt; mso-fareast-font-family: 宋体; mso-bidi-font-family: "Times New Roman"; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA;">10M</span><span style="FONT-FAMILY: 宋体; FONT-SIZE: 10pt; mso-ascii-font-family: "\000B _GB2312"; mso-hansi-font-family: "\000B _GB2312"; mso-bidi-font-family: "Times New Roman"; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA;">接入。</span>
时间:
2007-5-23 14:09
作者:
yyj830211
<p>仔细看了，解了我的疑惑，谢谢</p>
时间:
2007-5-26 15:58
作者:
happyyou
还可以!
时间:
2007-5-26 15:58
作者:
myheart527
<p>不错</p><p>分析的不错</p><p>最后一个问题也回答的很对</p>
时间:
2007-5-26 16:41
作者:
佛祖心中留
弄清楚了！谢谢1
时间:
2007-5-27 12:26
作者:
tyfyhl
<p>谢谢</p><p>学习</p><p>收藏</p>
时间:
2007-5-29 20:46
作者:
43432258
<p>好东西，学习</p>
时间:
2007-6-2 21:13
作者:
阁阁
看不大懂~~~~~~
时间:
2007-7-13 15:41
作者:
瑞光
<p>现在 基本了解清楚了 </p>
时间:
2010-7-27 16:55
作者:
硝烟灭火
好东西，学习
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