Verilink XEL XSP-100 SHARK IAP (9SA-USRS-9.0R1.02) Product Manual - Manual (Page 248)

Chapter 10 Chapter 10.Appendix A: Glossary
Appendix: 10-6 XEL P/N & Release: 9SA-USRS-9.0R1.02 SHARK™ IAD User's Guide
DS0 Digital or data signal level 0. The basis of a 64-kbps digital data stream.
DS1 Digital signal level 1. The 1.544-Mbps T1 line.
DSL Digital Subscriber Line. A generic name for digital services provided by local telephone
companies. It often refers to an ISDN BRI channel in which High speed digital services are
provided across four ordinary copper lines.
DSLAM DSL Access Multiplexer. Access node in a central office that multiplexes several DSL lines for
connection to a remote switch or router.
DSP Digital Signal Processor. A specialized digital microprocessor that performs calculations on
digitized signals that were originally analog (e.g., voice) and then sends the results on.
DSU Data Service Unit. A DSU interfaces to a T1 digital circuit, in combination with a CSU. The
DSU converts the customer data stream to bipolar format for transmission.
DSX Digital System Cross Connect-Frame. A bay or panel to which T1 lines and DS1 circuit packs is
wired and that permits cross-connections by patch cords and plugs. A DSX panel is used in small
offices where only a few digital trunks are installed.
DTE Data Terminal Equipment. Network node that passes information to a DCE (modem) for
transmission. A computer or router communicating through a modem is an example of a DTE
device. The name applied to a piece of equipment such as personal computers, SNA control
units, automatic teller machines, reservation terminals, etc.
DTMF Dual Tone Multi-Frequency. A type of signaling consisting of a push button or touch-tone dial
that sends out two discrete tones, which are picked up and interpreted by telephone switches.
DTR Data Terminal Ready. Circuit activated to indicate to a modem (or other DCE) that the computer
(or other DTE) is ready to send and receive data.
- E -
E&M S
IGNALING
Conventional telephony arrangement that uses separate leads, called, respectively, the “E” (“ear”
or "earth") lead and “M” (“mouth” or "magnet") lead, for signaling and supervisory purposes.
ECHO INTERVAL
Frequency with which the router sends out echo requests.
ENCAPSULATION
Technique used to enclose information formatted for one protocol, such as AppleTalk, within a
packet formatted for a different protocol, such as TCP/IP.
ENCRYPTION
The application of a specific algorithm to a data set so that anyone without the encryption key
cannot understand the information.
ESF Extended Super Frame format. A framing format that allows a maintenance channel and error-
detection capability on a DS1.