You are here

Glossary
1 8 A B C D E F G H I J L M N O P Q R S T U V W
S
  • Serial Transmission

A common mode of transmission, where the character bits are sent sequentially one at a time instead of in parallel.

  • SFP

The small form-factor pluggable (SFP) is a compact, hot-pluggable transceiver used for both telecommunication and data communications applications. The form factor and electrical interface are specified by a multi-source agreement (MSA). It interfaces a network device motherboard (for a switch, router,media converter or similar device) to a fiber optic or coppernetworking cable. It is a popular industry format jointly developed and supported by many network component vendors. SFP transceivers are designed to support SONET,Gigabit Ethernet, Fibre Channel, and other communications standards. Due to its smaller size, SFP obsolesces the formerly ubiquitous gigabit interface converter (GBIC).

  • Shielded Twisted Pair

Twisted pair cabling is a type of wiring in which two conductors of a single circuit are twisted together for the purposes of canceling out electromagnetic interference (EMI) from external sources; for instance, electromagnetic radiation from unshielded twisted pair (UTP) cables, and crosstalk between neighboring pairs. It was invented by Alexander Graham Bell.

  • Shielding

The protective enclosure surrounding a transmission medium, designed to minimize electromagnetic interference (EMI/RFI).

  • Single Mode

Describing an optical wave-guide or fiber that is designed to propagate light of only a single wavelength (typically 5-10 microns in diameter).

  • SNMP

Simple Network Management Protocol
The Internet standard protocol for managing nodes on an IP network.

  • SSH

Secure Shell
A network protocol that allows data to be exchanged over a secure channel between two computers. Encryption provides confidentiality and integrity of data.

  • STP

Spanning Tree Protocol
The Spanning Tree Protocol (STP) is a network protocol that ensures a loop-free topology for any bridged Ethernet local area network. The basic function of STP is to prevent bridge loops and the broadcast radiation that results from them. Spanning tree also allows a network design to include spare (redundant) links to provide automatic backup paths if an active link fails, without the danger of bridge loops, or the need for manual enabling/disabling of these backup links.
Spanning Tree Protocol (STP) is standardized as IEEE 802.1D. As the name suggests, it creates a spanning tree within a network of connected layer-2 bridges (typically Ethernet switches), and disables those links that are not part of the spanning tree, leaving a single active path between any two network nodes.
STP is based on an algorithm that was invented by Radia Perlman while she was working for Digital Equipment Corporation.

  • Synchronous Transmission

Transmission in which data bits are sent at a fixed rate, with the transmitter and receiver synchronized.