| Glossary: S |
| S/N |
See Signal-to-Noise ratio (SNR).
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| S1DN |
Stage 1 Distribution Network (part of SMAS)
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| SAM |
System Administration Manager
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| SAR |
Segmentation and Reassembly
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| SARTS |
See Switched Access Remote Test System.
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| SBD |
Sound Board or Simulation-Based Design
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| SCID |
SONET Circuit Identifier
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| SCP |
See Service Control Point.
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| SCRC6 |
Severe Cyclic Redundancy Check Error
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| SCU |
Shelf Controller Unit
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| SDE |
Simple Delay Equalization
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| SDH |
Synchronous Digital Hierarchy
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| SDL |
Smart Data Loopback
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| SDP |
Simple Device Protocol
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| SDSL |
Symmetrical DSL
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| SDTC |
Super DCS Testing Concentrator
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| Secondary channel |
The secondary channel is a low-speed data channel on a DDS circuit that accompanies the primary DDS channel for 2.4 4.8 9.6 and 56-kbps service; it uses every third network control bit (max.).
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| Section |
The smallest unit of a SONET service. It is the span between regenerators and other section-terminating equipment.
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| SEF |
Severely Errored Frame
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| SEFS |
Severely Errored Framing Second
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| Service Control Point (SCP) |
The database for SS7 tables.
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| Service Switching Point (SSP) |
The end office switch typically 5E or DMS 100.
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| SES |
See Severely Errored Seconds.
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| Severely errored second (SES) |
(DS1): A second which has an equivalent error ratio greater than 1-in-1000. In SF a second with one or more LOSs or frame sync losses six or more framing bit errors or 1544 or more BPVs. In ESF a second with one or more LOSs or frame sync losses 320 or more CRC-6 errors or 1544 or more BPVs. On unframed circuits a circuit with one or more LOSs or 1544 or more BPVs.
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| Short-haul facilities |
Facilities that stay within the digital serving area. Can provide intrastate or interstate services with distances typically less than 50 miles.
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| SID |
Site Identifier Source Identifier or System Identification
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| SIF |
SONET Interoperability Forum
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| Signal loss |
A received signal that has 125 plus or minus 25 consecutive zeros. Or the signal is of a received level less than 32 dB below the DSX level.
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| Signal status |
The absence or presence of a signal.
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| Signal-to-noise ratio (SNR) |
The ratio expressed in decibels of the average signal power to the average noise power at a given point in a transmission path.
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| Signaling System 7 (SS7) |
Packet switching network protocol used between intelligent nodes in the PSTN to provide signaling to establish and disconnect calls (and other related services including 800 number translation caller ID store and forward ring back concurrent data etc.).
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| Signaling Transfer Point (STP) |
A packet switch optimized for SS7 message handling.
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| Simple Network Management Protocol (SNMP) |
A protocol used to manage and monitor networks based on TCP/IP.
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| Singing return loss (SRL) |
The difference in dB between the level of two separate composite-frequency signals sent into a circuit and the level of the echo of that signal as it reaches the point of application. The SRL-LO composite-frequency signal normally contains spectral distributions between 260 Hz and 500 Hz at equal amplitudes. The SRL-HI composite-frequency signal normally contains spectral distributions between 2200 Hz and 34000 Hz at equal amplitudes.
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| Single-ended testing |
A test equipment configuration used for cooperative testing between test units at two points on the circuit.
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| Single-frequency (SF) signaling |
A method of conveying dial-pulse and supervision signals from one end of a trunk or line to the other. This method uses the presence or absence of a single specified frequency (usually 2600 Hz).
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| SLC™ 96 |
Subscriber Loop Carrier 96-channel system
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| SLU |
Spare Line Unit
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| SmartestPlus™ Interactive Dialogs |
A product that works with REACT 2001™. Each dialog performs a complex group of testing operations and provides intelligent assistance in fault isolation. Detailed help screens assist in choosing test options and interpreting results.
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| SMARTEST™ |
A REACT option that enables testers to schedule automatic unattended testing.
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| Smartjack |
An interface connector which provides T1 loopbacks at the network interface. Used along with channel service units at the customer's site.
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| SMAS |
See Switched Maintenance Access System.
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| SMA™ |
Services Management Architecture™
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| SMB |
Small to Medium Business
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| SMDS |
See Switched Multimegabit Data Service.
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| SME |
Small to Medium Enterprise or Subject Matter Expert
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| SMIT |
System Management Interface Tool
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| SMJ |
Smartjack
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| SMPT |
Simple Mail Transport Protocol
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| SMUX |
SONET multiplexer
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| SMX |
SniffMaster™ for X
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| SNA |
System Network Architecture
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| Sniffer™ |
A line of protocol analysis products.
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| SNMS |
SONET Network Management System
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| SONET |
Synchronous Optical Network
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| SORD |
Service Order Retrieval and Distribution
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| SOS |
Surveillance Operating System
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| Spectrum testing |
A testing method used to measure and view the signal energy (power levels) across a given frequency range. Spectrum testing is used to evaluate unwanted interference signals as well as the power spectral density of known signals.
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| SPID |
See Service Profile Identifier.
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| Service Profile Identifier (SPID) |
The generic SPID format comprises 14 digits: the first 10 digits are the area code and telephone number of the ISDN line; the second two digits identify the switch to which the terminal device is connected; and the last two numbers identify the specific terminal device being connected on that ISDN line.
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| Split-access testing |
Testing in either a loopback or single-end configuration that disrupts the signal being tested.
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| SPRM |
Supplemental Performance Report Message
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| SQL |
See Structured Query Language.
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| SRDC |
Subrate Digital Cross-connect
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| SRDM |
Subrate Digital Multiplexer (part of DDS)
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| SRS |
Switched / Switch Request to Send
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| SSC |
Special Services Center
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| STM |
Synchronous Transfer Mode
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| Straightaway test |
Tests in which the transmitter and receiver are connected to physically different points of a circuit under test usually in different offices. The transmitter originates tests on the circuit and the receiver displays the results. This differs from loopback testing in which the transmitter and the receiver are at the same point.
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| Streaming |
Nonstop transmission of signals down a data line from a defective piece of equipment such as a modem. Streaming equipment ties up a multipoint circuit with false signals and prevents other equipment from using the circuit.
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| Stress test |
"A data test pattern used to determine a circuit's ability to accurately carry digital signals with a ""low ones density."""
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| Structured Query Language (SQL) |
A relational database language (ANSI standard) that consists of a set of facilities for defining manipulating and controlling data.
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| STS |
Synchronous Transport Signal
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| Subrate digital multiplexer |
A unit in the hub office that combines several data streams at or below some basic rate (2.4 4.8 9.6 or 56 kbps) into a single 64-kbps (DS0B) signal.
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| Subrate frame slip |
A slip that occurs when a subrate framing bit is lost or duplicated but the framing pattern integrity is otherwise maintained.
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| Subrate framing errors |
Incorrect framing bits from the DS0B signal under test.
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| Subscriber-Network Interface (SNI) |
User-to-Network Interface (UNI) defined specifically for SMDS. Based on the IEEE 802.6 access protocol present Layer 1 speeds are subrate (N X 64 kbps) DS1 (1.544 Mbps) and DS3 (44.736 Mbps). Interfaces for the future are expected to follow the Broadband-ISDN access rates of 155 Mbps.
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| SVC |
Switched Virtual Circuit
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| SVP |
Switched Virtual Path
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| Switched 56 |
A data circuit that operates at 56 kbps over switched virtual circuits.
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| Switched Access Remote Test System (SARTS) |
An operations support system that permits remote testing of end offices. The SARTS system communicates with these end offices through the public data packet network.
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| Switched Maintenance Access System (SMAS) |
A system that provides remote circuit testing for intermediate and end offices. It allows a tester to access and test a circuit without the aid of another tester in a distant office.
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| Switched Multimegabit Data Service (SMDS) |
A high-speed intraLATA data transport service by which public networks can transport information quickly across areas wider than those served by local area networks. This packet-switching data service provides wide area data transport up to 45 Mbps. SMDS offers group addressing connectionless transport and strict packet delay objectives.
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| SX signaling |
A signaling path over a voice wire pair that uses the two wires of the circuit in parallel. The path is derived by connecting the midpoints of repeating coils at each end of the channel to signaling units that use the ground for a return path.
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| Synchronization lost seconds |
Seconds of lost DS1 synchronization.
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| SYSGEN |
System Generation
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| System administration |
The configuration and operation of the system.
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| System controller node |
The location of the REACT system controller equipment and the system console. The system console node allows maintenance of the REACT software. Maintenance tasks include installing updating modifying and backing up the REACT software and circuit databases.
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| System management |
Initial and ongoing maintenance of a computer’s configuration.
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