E
extension number - an arbitrary number of two to five digits that matches a station to a particular user.
F
Firewall - a set of related programs, located at a network gateway server, that protects the resources of a network from users of other networks.
FLASH - a sudden brief signal. Activated by depressing the flash key on the telephone pad if one has been configured, or by a quick press and release of the receiver button (switch hook).
FXS - Foreign Exchange Subscriber. An analog interface for direct connection of a telephone set to a digital multiplexer.
G
Gateway - allows H.323 terminals to communicate with terminals configured to other protocols by converting protocols. A gateway is the point where a circuit- switched call is encoded and repackaged into IP packets.
GMT - Greenwich Mean Time. Mean solar time of the meridian at Greenwich, England, used as the basis for standard time throughout the world.
H
H.323 - An International Telecommunications Union
http or HTTP - Hypertext Transfer Protocol. The Internet protocol used to manage communications between Web clients (browsers) and servers.
I
IMAP4 - Internet Message Access Protocol - Version 4.
IP Address - a
ISP - Internet Service Provider.
J
jack - the mate for a plug. Used to connect two pieces of equipment together.
