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【转】E1电路

2011-07-15 23:06:54| 分类：资料 | 标签： |举报 |字号大中小订阅

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这几天调程序时用了一对E1转Ethernet设备，下面是百度来的:

T-1 是一种数字电路，采用数字信令等级1（DS-1）的信号格式并以 1.544Mbps 的网速在公共交换电话网络（PSTN）上传送音频/数据信息。T-1 能够传输多达24个带宽为 64Kbps（DS0）且未经压缩的音频/数据信道。在欧洲，E-1 与上述的 T-1 相对等，不同的是，E-1 传输信息的速率是 2.048Mbps。 E-1 被用来传输 30.64Kbps 的音频/数据通话信道（DS0），再加上一个 64Kbps 的信号信道和一个 64Kbps 帧同步及维持信道。 T1/E1 电路是一个专门电路，通常由两部分组成：本地回路和载波电路。T1/E1 电路是数字信号多路复用方案的第一个多元层面。T1 使用3级时钟（Stratum 3 Clock）来维持线上时钟。

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