Xblue Networks X-50 Installation Manual page 249

Subnet Mask Address
– The Subnet Mask Address is used to segment (divide) a network into multiple networks.
Also, using a complex mathematical formula, the Subnet Mask Address is used to determine how many IP Addresses
are available per Class.
Basically, the lower the number, the more IP Addresses are available. For example, if the Subnet Mask Address is
255.255.255.0, only the last number is 0, so the maximum number of IP addresses possible is 254 (both zero 0 and
255 are reserved). If the Subnet Mask Address is 255.255.0.0 then the possible number of IP addresses becomes 255
or 66,000. Finally if the Subnet Mask Address is 255.0.0.0 then the possibilities are 255
Subnet Mask Address consists of a group of 4 numbers (Octets), each ranging from 0~255, and is usually written as
xxx.xxx.xxx.xxx.
Subnet Mask
255.255.255.0
255.255.240.0
255.255.224.0
255.255.192.0
255.255.128.0
255.255.0.0
TDM – Time Division Multiplexing -
URL– Uniform (Universal) Resource Locator -
Resource Identifier, which is used to retrieve websites using a name rather than an IP Address.
Vocoders –
A voice encoder, known as a Vocoder, defines the voice compression and decompression that will be
used for the voice transmission. Currently, all Voice over IP connections are full duplex, so every call opens bandwidth
for "send, Receive, and Overhead (data signalling)". Common Vocoders are G.711, G.728, G.729, G.723.1
VoIP – Voice over Internet Protocol –
using Internet Protocol, over a LAN, WAN or Internet.
VPN –
A Virtual Private Network is a communications network "tunneled through" another ne work, creating a
larger dedicated network. The "tunnel" is built using special security protocols, which are established and accepted by
all parties. Once the "tunnel" is established the locations will continuously send a "keep alive" signal to keep the loca-
tions connected.
WAN – Wide Area Network –
a "Network". A WAN is used with multiple locations, and has no physical boundaries. It is actually possible to have a
WAN that spans the globe.
Max Subnets
1
16
32
64
128
255
The division of voice transmission, based on time.
This is a subset, along with Uniform Resource Name, of Uniform
Voice over IP is a protocol that defines the transport of voice packets,
A WAN network devices to share and access files through a series of wires known as
XBLUE Networks
Glossary of Terms
3
or 16.8 million addresses. The
Client Devices
254
65,280
261,120
1,044,480
4,177,920
16,581,375
2
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