同步数字系统：synchronous digital hierarchy
国际标准：international standard
信号格式：signal format
网络节点接口：network node interface
支路信号：tributary signals
数字交叉连接：digital cross-connection
网络管理：network management
网络维护：network maintenance
网络运营者：network operators
传输速率：transmission rate
支路映射：tributary mapping
灵活性：flexibility
用户业务：subscriber services
覆盖层：overlay levels
制造商：manufacturer
同步传输帧：synchronous transmission frame
线路终端复用器：line terminal multiplexer
分插复用器：add-drop multiplexer
再生中继器：regenerator
灵敏度：sensitivity
虚容器：virtual container
成帧字节：framing bytes
段开销：section overhead
端到端传输：end-to-end transmission
误码监视：error monitoring
信号处理节点：signal processing nodes
净负荷：payload
指针：pointer
同步传输系统：synchronous transmission system
覆盖NNI 的标准：the standard covering the NNI
国际标准接口：the international standard interface
直接同步复用：direct synchronous multiplexing
灵活的通信联网：flexible telecommunication networking
点对点的传输技术：point-to-point transmission technology
先进的网络管理：advanced network management
不同厂家提供的设备：the equipment supplied by different manufacturers
提供的灵活性：the flexibility provided by SDH
同步复用设备的运营者：operator of synchronous multiplexers
电信联网：telecommunication networking
支路信号：tributary signals
维护能力：maintenance capabilities
统一的电信网络基础结构：unified telecommunication network infrastructure
组件：building blocks
终端复用器：terminal multiplexer
贯通方式：through-mode fashion
同步数字交叉链接：synchronous DXC
可变带宽：varying band
各个支路信号：individual tributary signals
传输系统：transport system
光载体：optical carrier
二维图形：2-dimensional map
传输次序：the order of transmission