Appendix D Terminologies
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Appendix D: Terminologies
802.1p
An IEEE standard for QoS. It uses 3 bits allowing switches to
reorder packets based on priority level.
802.1Q
An IEEE standard for QoS. It provides VLAN identification, priority
and QoS levels.
10BaseT
A type of IEEE802.3 Ethernet network providing 10 Mbit/s with a
maximum segment length of 100 meters.
Auto Attendant
A voice mail system feature answering calls with prerecorded voice
prompts to guide callers.
Buffer
A temp storage area that compensates for a difference in
transmission speeds timing.
Caller ID
A telephone company service displaying callers’ number and/or
name.
CDR
Call Detail Records. A database record contains data about a
specific call.
CO
Central Office. A telephone company site that hosts PSTN switching
equipment.
CO Line
Also known as trunk line. A telephone line from a telephone
company.
CoS
Class of Service. A classification assigned to users giving them
different rights or privileges.
CODEC
Coder/Decoder. A hardware or software method coverts analog
audio or video signal s to digital and vice versa.
Call Restriction
The national numbering plan defines area codes and long distance
codes.
DHCP
Dynamic Host Configuration Protocol. A method of automatically
assigning IP settings to network-enabled devices.
DNS
Domain Name System. It is used on for translating name of nodes
into IP addresses.
DTMF
Dual Tone Multi-Frequency. The pushed keypad button generates a
pair of tones for identifying the button.
FXO
Foreign Exchange Office. An analog trunk side connection between
a CO and PBX system.
FXS
Foreign Exchange Station. An analog line side connection between a
PBX system and a POTS telephone.
G.711
Also knows as PCM. A compression standard encoding/decoding
