Xblue Networks X-50 - Manual (Page 244)

Glossary of Terms
244 XBLUE Networks
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Differentiated Services Code Point (DSCP) – The DSCP is part of the overall Quality of Service (QOS) strat-
egy.
DMZ – In computer network security there is a special location commonly called the Demilitarized Zone but really
stands for Data Management Zone, which can be a physical or logical subnetwork that is exposed to external ser-
vices such as the Internet.
DNS – A Domain Name System is the “Phone Book” for the Internet. It translates “Human Relatable” names such
as www.xbluenetworks.com into the numeric IP Address. The DNS can be a local or remote server, and it is a
essential part of today’s Internet.
(DHCP) Dynamic Host Configuration Protocol – A dynamic IP address is assigned by a DHCP server, such as
a router or network file server. Each time a network device is powered on it is “leased” (issued) an IP Address
which has a scheduled expiration time. Once the lease expires the address may be released to the same device or
another device.
FXO - Foreign Exchange Office - is where a standard telephone line is connected and requires telephone line
signaling interface for standard analog telephone lines also known as “POTS”, Plan Old Telephone Service. When
the telephone line is taken off hook, the FXO signals the telephone line provider by closing the “loop relay”, which
signals the telephone line provider that it is off hook and should receive dial tone.
FXS - Foreign Exchange Station - is where a standard Analog or Single Line Telephone is connected to the sys-
tem. The system provides talk battery, dial tone, generates ring voltage and generates DTMF Tones for the tele-
phone line provider to process and make calls.
Gateway – A Gateway, sometimes called a Media Gateway, is the device that joins dispirit ne works; similar to a
MUX, taking a T1 and converting it to a standard Loop-Start CO Line.
Gatekeeper – A Gatekeeper maintains a registry of remote devices. Each remote device must register and be
authenticated to be granted access to the “Voice Network”. In addition, it provides address translation and pro-
vides other services such as bandwidth management and locating gat ways.
H.323 – the originally created as a multi-media protocol, later to incorporate Voice over IP. It is the most mature
and widely used protocol.
Intranet – An Intranet is a private computer network that an Internet Protocol backbone. This could be consid-
ered a private version of the Internet.
Internet – The Internet is a series of interconnected computers and computer networks that transmit and
receives data using a packet switching protocol known as Internet Protocol. The Internet is generically known as
the “World Wide Web”.
IGW – Internet Gateway – A gateway joins two or more disparate networks, such as an intranet (LAN) from
the Internet (WAN), or when separating a normal LAN from wireless guests. Generally, a gateway will have at least
one each WAN and LAN port.
IGMP – Internet Group Management Protocol – The protocol that manages multicast groups to more effi-
ciently stream multicast groups, such as Video and Gaming.