Xblue Networks X-50 User Manual
Page 249
XBLUE Networks
249
Glossary of Terms
13
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
2
or 66,000. Finally if the Subnet Mask Address is 255.0.0.0 then the possibilities are 255
3
or 16.8 million addresses. The
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.
TDM –
Time Division Multiplexing -
The division of voice transmission, based on time.
URL–
Uniform (Universal) Resource Locator -
This is a subset, along with Uniform Resource Name, of Uniform
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 –
Voice over IP is a protocol that defines the transport of voice packets,
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 WAN network devices to share and access files through a series of wires known as
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.
Subnet Mask
Max Subnets
Client Devices
255.255.255.0
1
254
255.255.240.0
16
65,280
255.255.224.0
32
261,120
255.255.192.0
64
1,044,480
255.255.128.0
128
4,177,920
255.255.0.0
255
16,581,375