Carrier Access Access Navigator user manual Stratum

Glossary

Stratum	Stratum or Stratum Level refers to the accuracy of the clock source used to synchronize
	SONET communications systems. Accuracy is important in maintaining communications
	across a network. During local network failures, a backup clock source is used to maintain
	network timing. But when the backup clock becomes temporarily isolated because of an
	equipment or line failure, the clock phase will drift slowly until the communications link
	eventually falls out of synchronization. Stratum 1 is the primary SONET clock source
	obtained from a Cesium beam time standard located in Paris, France. Stratum 2 is less
	accurate, but can keep a network synchronized for 3 to 5 days. Stratum 3 and Stratum 4 are
	each less accurate (and less expensive) and can provide backups for shorter time periods.

Symmetrical

Digital

Subscriber Line

Superframe

Telcordia

Telnet

TR-08

SDSL. A service providing data transfer rates of up to 1 megabit per second in both directions (symmetrical). SDSL is preferred over Asymmetrical DSL (ADSL) for most business networking applications. A low-cost SDSL router can provide one or more Ethernet ports for simple connection to the subscriber's computers or local area network.

SF. Any structure made of multiple lower-rate frames.

Previously known as Bellcore (Bell Communications Research), the company now known as Telcordia Technologies was created during the divestiture of the Bell System in 1984 to serve the Bell operating companies by providing a center for technological expertise and innovation.

Telecommunications network protocol. A terminal emulation protocol that runs on top of TCP/IP. Telnet lets a user log into a remote host or server. A user name and password are normally required. Telnet provides a simple command line interface using text characters. Originally developed for ARPAnet, Telnet is defined in Internet STD 8 and RFC 854

A Telcordia technical requirement for digital loop carrier systems based on the SLC-96 terminal. This interface transports 96 analog telephone lines over four T1 lines connecting the switch to the TR-08 terminal. Terminals can have up to four shelves (A, B, C, D) with each shelf terminating up to 24 analog voice lines. The switch manages the terminal through the out-of-band SLC-96 digital data link (DDL) channel on the T1 connection to Shelf A

Transmission TCP. A transport layer protocol that offers connection-oriented, reliable stream service

Control between two hosts. TCP is the primary transport protocol used by TCP/IP applications.

Protocol

Trap

Trunk level 1

A monitoring function that triggers an alarm or sends a message when a certain event occurs or a threshold value is exceeded.

T1. A digital transmission link used in North America to transport data at 1.544 million bits per second. T1 is a facility or service normally delivered over two pairs of copper wires, one pair for transmit and one pair for receive. Fiber T1 (FT1) uses fiber optics instead of copper. T1 is based on the DS1 time division multiplexed (TDM) signal carrying 24 DS0 channels

GlossaryGlossaryGlossaryGlossary-12 August 2003 Access Navigator - Release 1.8