User manual

DAG Series User Manual

Dinstar Technologies Co., Ltd.

5. Glossary

ADSL Asymmetric Digital Subscriber Line: Modems attached to twisted pair copper wiring that transmit

from 1.5 Mbps to 9 Mbps downstream (to the subscriber) and from 16 kbps to 800 kbps upstream,

depending on line distance.

AGC Automatic Gain Control is an electronic system found in many types of devices. Its purpose is to

control the gain of a system in order to maintain some measure of performance over a changing range

of real world conditions.

ARP Address Resolution Protocol is a protocol used by the Internet Protocol (IP) [RFC826], specifically

IPv4, to map IP network addresses to the hardware addresses used by a data link protocol. The

protocol operates below the network layer as a part of the interface between the OSI network and OSI

link layer. It is used when IPv4 is used over Ethernet

CODEC Abbreviation for Coder-Decoder. It's an analog-to-digital (A/D) and digital-to-analog (D/A)

converter for translating the signals from the outside world to digital, and back again.

CNG Comfort Noise Generator, generate artificial background noise used in radio and wireless

communications to fill the silent time in a transmission resulting from voice activity

detection.

DATAGRAM A data packet carrying its own address information so it can be independently

routed from its source to the destination computer

DECIMATE To discard portions of a signal in order to reduce the amount of information to be

encoded or compressed. Lossy compression algorithms ordinarily decimate while

sub-sampling.

DNS Short for Domain Name System (or Service or Server), an Internet service that translates

domain names into IP addresses

DSP Digital Signal Processor. A specialized CPU used for digital signal processing. Allywll

products all have DSP chips built inside.

DTMF Dual Tone Multi Frequency. The standard tone-pairs used on telephone terminals for

dialing using in-band signaling. The standards define 16 tone-pairs (0-9, #, * and A-F)

although most terminals support only 12 of them (0-9, * and #).

FXO Foreign exchange Office. An FXS device can be an analog phone, answering machine, fax,

or anything that handles a call from the telephone company like AT&T. They should also

operate the same way when connected to an FXS interface. • An FXS interface will accept

calls from FXS or PSTN interfaces. All countries and regions have their own standards. •

FXS is complimentary to FXS (and the PSTN).

FXS Foreign exchange Station. An FXS device has hardware to generate the ring signal to the

FXS extension (usually an analog phone). • An FXS device will allow any FXS device to

operate as if it were connected to the phone company. This makes your PBX the

POTS+PSTN for the phone. • The FXS Interface connects to FXS devices (by an FXS

interface, of course).

DHCP The Dynamic Host Configuration Protocol (DHCP) is an Internet protocol for automating

the configuration of computers that use TCP/IP. DHCP can be used to automatically assign IP

addresses, to deliver TCP/IP stack configuration parameters such as the subnet mask and

default router, and to provide other configuration information such as the addresses for