Bandwidth - Transmission capacity of a communications line, which also means the speed of data can be transferred.

Bps - Bits per second

DSL - Digital Subscriber Line -  high-speed connection that uses the same wires as a regular telephone line.

DSP - Digital Signal Processing

Dynamic IP Address - IP Address that is temporary assigned to a network device by an ISP.

Echo Cancellation - A technology that provide near-wireline voice quality across a wireless carrier's network.

Ethernet - 10Mb/100Mb baseband local area network

FXO - Foreign exchange office - The interface on VoIP device for connecting to an analog PBX extension.

FXS - Foreign exchange station - The interface on VoIP device for connecting to phones, FAX machines.

H.323 - Standard call setup Protocol for VoIP communications

IP - Internet Protocol

IP Address - An address used by IP data networks to identify the location of a device on a network.

IP Gateway - A device that coverts voice and fax call in real time between PSTN and IP networks

IP Gatekeeper - H.323 entity that defines the policies that govern the dialing plan, bandwidth consumption, users detail, etc.

ISDN - Integrated Services Digital Network

Jitter - Variability in packet arrival at the destination.

LAN - Local Area Network - two or more computers linked together in the same network location.

PBX - Private Branch Exchange - A circuit switching facility for phone extension line within the same PSTN connection.

PSTN - A telephone network that routes voice calls from one location to another.

QoS - Quality of Service - management tool for the service provided (e.g. bandwidth management) to the users

Router - Device that connects two networks which are using the same networking protocol

SIP - Session Initiation Protocol - A signal protocol used to setup the telephony, and other communication devices over the internet.

Static IP Address - IP Address that is permanently assigned to a network device by an ISP.

Subnet Mask - A mask used to determine what subnet of an IP address belongs to.

VoIP - Voice over Internet Protocol

WAN - Wide Area Network - Connection of multi LANs (more than two).