Cisco 10000 Series Configuration Manual page 358

Glossary
S
Synchronous Digital Hierarchy. European standard that defines a set of rate and format standards that
SDH
are transmitted using optical signals over fiber. SDH is similar to SONET, with a basic rate of 155.52
Mbps, designated as STM-1. See also
Super frame. Common framing type used on T1 circuits. SF consists of 12 frames of 192 bits each, with
SF
the 193rd bit providing error checking and other functions. SF has been superseded by ESF, but is still
widely used. Also called D4 framing. See also ESF.
See SNMP.
Simple Network
Management
Protocol
Simple Network Management Protocol. Network management protocol used almost exclusively in
SNMP
TCP/IP networks. SNMP provides a means to monitor and control network devices, and to manage
configurations, statistics collection, performance, and security. See also SNMP2.
SNMP Version 2. Version 2 of the network management protocol. SNMP2 supports centralized as well
SNMP2
as distributed network management strategies, and includes improvements in the SMI, protocol
operations, management architecture, and security. See also SNMP.
Synchronous Optical Network. High-speed synchronous network specification developed by Bellcore
SONET
and designed to run on optical fiber. STS-1 is the basic building block of SONET. It was approved as
an international standard in 1988. See also
Synchronous Payload Envelope. The major portion of the SONET frame format used to carry the STS-1
SPE
signal; it is divided into an information payload section and a transport overhead system. SPE is used
to address three payload structures: direct to STS-1 line rate muliplexing; asynchronous DS3
multiplexing; and synchronous DS3 multiplexing.
Synchronous Transport Module level 1. Basic building block signal of SDH, operating at 155.52 Mbps.
STM-1
Faster SDH rates are defined as STS-n, where n is a multiple of 155.52 Mbps. See also SDH.
Synchronous Transport Signal level 1. Basic building block signal of SONET, operating at 51.84 Mbps.
STS-1
Faster SONET rates are defined as STS-n, where n is a multiple of 51.84 Mbps. See also SONET.
Subrate DS3
A generic term to describe a process in which the bandwidth of a clear channel DS3 is limited to a lower
rate. Many proprietary formats exist.
See SF.
Super Frame
Synchronous Digital Hierarchy. European standard that defines a set of rate and format standards that
SDH
are transmitted using optical signals over fiber. SDH is similar to SONET, with a basic rate of 155.52
Mbps, designated as STM-1. See also
Super frame. Common framing type used on T1 circuits. SF consists of 12 frames of 192 bits each, with
SF
the 193rd bit providing error checking and other functions. SF has been superseded by ESF, but is still
widely used. Also called D4 framing. See also ESF.
Cisco 10000 Series Router Line Card Configuration Guide
GL-8
SONET and STM-1.
SDH and STS-1.
SONET and STM-1.
OL-8834-04