APPENDIX
ELX4 -60
Rugged CCTV
2003.05.21 (v 1.0)
69
Appendix #2 Utilizing IP Addresses on Local Network
#2.1 Introduction
Most of our businesses are done via Internet, lately. We play with information by transmitting through e-
mails and searching the world of Internet. IP address is what we utilize to access to the Internet.
Currently used IP addresses are limited. And there are 5 classes’ networks in the world for now, and a
network contains lots of IP addresses. A network can hold limited IP addresses. The numbers depend on
network class. 5 classes are from A to E, and the most common one is C class network.
#2.2 IP construction and Network class
1) IP construction
( (xxx: 0 – 255)
e.g. 192.168.1.1
2) Network class
A class
: A network that contains IP addresses from 0 to 127 at room ‘X1’.
Network ID: X1
Host ID: X2, X3, X4
Total number of A-class networks is 128 in the world.
B class
: A network that contains IP addresses from 127 to 191 at room ‘X1’.
Network ID: X1, X2
Host ID: X3, X4
Total number of B-class networks is 65,534 in the world.
C class
: A network that contains IP addresses from 192 to 223 at room ‘X1 ’.
Network ID: X1, X2, X3
Host ID: X4
It is the most common network in the world, and the total number of C-class networks is
2,097,152
D class
: A network that contains IP addresses from 224 to 239 at room ‘X1 ’. D-class network is for
multicasting, and it is not allowed to use for com mon users.
E class
: A network that contains IP addresses from 240 to 225 at room ‘X1’. E-class network is
reserved.
xxx
xxx
xxx
xxx
X1
X2
X3
X4
