
Switching restoration
time
It refers to the period of time between the start of detecting and the moment when the
line is switched back to the original status after protection switching occurs in the MSP
sub-network.
Synchronization Status
Message
A message that carries quality levels of timing signals on a synchronous timing link.
Nodes on an SDH network and a synchronization network acquire upstream clock
information through this message. Then the nodes can perform proper operations on their
clocks, such as tracing, switching, or converting to holdoff, and forward the
synchronization information to downstream nodes.
Synchronous Digital
Hierarchy
A transmission scheme that follows ITU-T G.707, G.708, and G.709. It defines the
transmission features of digital signals such as frame structure, multiplexing mode,
transmission rate level, and interface code. SDH is an important part of ISDN and B-
ISDN. It interleaves the bytes of low-speed signals to multiplex the signals to high-speed
counterparts, and the line coding of scrambling is used only for signals. SDH is suitable
for the fiber communication system with high speed and a large capacity since it uses
synchronous multiplexing and flexible mapping structure.
Synchronous source
A clock providing timing services to connected network elements. This would include
clocks conforming to Recommendations G.811, G.812 and G.813.
A.20 T
Tandem Connection
Monitor
In the SDH transport hierarchy, the TCM is located between the AU/TU management
layer and HP/LP layer. It uses the N1/N2 byte of POH overhead to monitor the quality
of the transport channels on a transmission section (TCM section).
TCM
TCP/IP
Transmission Control Protocol/Internet Protocol
TDM
Time Division Multiplexing
TIM
Trace Identifier Mismatch
Timeslot
Continuously repeating interval of time or a time period in which two devices are able
to interconnect.
Time Synchronization
Also called the moment synchronization, time synchronization means that the
synchronization of the absolute time, which requires that the starting time of the signals
keeps consistent with the UTC time.
TM
Terminal Multiplexer
TMN
Telecommunications Management Network
ToS
TPS
Trail management
function
A network level management function of the network management system. This function
enables you to configure end-to-end services, view graphic interface and visual routes
of a trail, query detailed information of a trail, filter, search and locate a trail quickly,
manage and maintain trails in a centralized manner, manage alarms and performance
data by trail, and print a trail report.
Transceiver
A transmitter and receiver housed together in a single unit and having some circuits in
common, often for portable or mobile use.
OptiX OSN 550 Multi-Service CPE Optical Transmission
System
Configuration Guide
A Glossary and Acronyms
Issue 02 (2011-06-30)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
A-29