ADM      Add-Drop Multiplexer                      分/插復用器
AIS      Alarm Indication Signal                   告警指示信號
ATM      Asynchronous Transfer Mode                異步傳輸模式
AU       Administrative Unit                       管理單元
AUG      Administrative Unit Group                 管理單元組
CRC      Cyclic Redundancy Check                   循環冗余校驗
CV       Coding Violation                          編碼違例
DXC      Digital Cross Connect                     數字交叉連接
FDDI     Fiber Distributed Data Interface          光纖分布式接口
ID       Identifier                                識別符
LOF      Loss Of Frame                             幀丟失
LOS      Loss Of Signal                            信號丟失
OAM      Operation Administration and Maintenance  運行、維護和管理
OOF      Out Of Frame                              幀失步
OW       Order Wire                                公務
PDH      Plesiochronous Digital Hierarchy          準同步數字體系
PSTN     Public Switched Telephone Network         共用電話交換網
RDI      Remote Defect Indication                  遠端缺陷指示
SDH      Sychronous Digital Hierarchy              同步數字體系
TUG      Tributary Unit Group                      支路單元組
VC       Virtual Container                         虛容器