The world wide IP Address (high level) is decided by Internet Assigned Number Authority (IANA). (Same as ITU-T for telephone number). Within Sri Lanka Internet Address authority is council for Information Technology (CINTEC). (Same as TRC for telephone number system) There are two version of IP addresses .IP Version 4 (IPV4) and IP version 6 (IPV6).the latter is also called IP next generation (IPng).IPv4 is a 32 bit scheme and IPv6 is 128 bit scheme.

Static ip address does not changing each and every time. As an example think about your home does not changing.To take an static IP address, you need to communicate with ISP(Internet service provider).ISP will issue a static IP address according to your request.Normally static IP addresses use for different purposes,such as web servers, remote servers.

If we have a network which is not connect to Internet(not a part of Internet) any IP address range can be used without obtaining any permission, However, it is not advisable to use any arbitrary IP Address since the network may be connect ed to Internet in future. In order to avoid such problems, ANA reserved some IP address ranges for private use. These IP Addresses are called private IP Addresses.

Class Private Network Address No. of Networks
A 1
B to 16
C to 256

The internet is a public computer Network which is spread all over the world. (Same as public Telephone number) Therefore, the IP address cannot be duplicated. Hence the allocation of IP addresses are controlled by the Internet assigned number authority (IANA) they have already allocated different IP address ranges to different countries. The government of each country assigned a government body to deal with IANA and the government body control of IP address within the country. The CINTEC assigns different range of IP Address to different Internet service providers (ISPs).The ISPs allocate IP addresses to their customers.

The 32 bit is represented in following manner. Byte 1.Byte 2.Byte 3.byte4 (Note: one byte is 8 bit) The minimum value of a byte is 00000000=0 The maximum value of a byte is 11111111=255 Therefore, the minimum and maximum IP addresses are and (This is called the dotted decimal representation) IP Address = Network ID + Host ID IP means Identification Part of the IP Address is allocated to Network ID and the remaining part is allocated to Host ID (Computer ID) If there are less networks, less number of bits can be allocated to network ID Therefore, IANA divided the IP Address into 3 main classes, called Class A, Class B, and Class C.

Class Net ID Host ID
A 1 Byte 3 Byte
B 2 Byte 2 byte
C 3 Byte 1 byte

The port number is a 16 bit binary number in the TCP. Therefore the port number is in the range of 0-65535.The port numbers are divided into three ranges. Well Known ports. Registered Ports. Dynamic Ports/Ephemeral ports

Well known Ports
The port numbers ranging from 0-1023.They are assigned to standard server processes such as FTP, Telnet. The numbers are assigned by IANA

Port Protocol Description
7 Echo Echoes a received datagram back to the sender.
9 Discard Discards any datagram that is received
11 Users Active user
13 Daytime Returns the data and the time
17 Quote Returns a quote of the day
19 Chargen Returns a string of characters
20 FTP, Data File Transfer Protocol(data connection)
21 FTP, Control File Transfer Protocol(Control connection)
23 TELNET Terminal Network
25 SMTO Simple Mail Transfer Protocol
53 DNS Domain Name Server
63 BOOTP Bootstrap Protocol
79 Finger Finger
80 HTTP Hypertext Transfer Protocol
111 RPC Remote Procedure Call

Registered Ports

The ports ranging from 1024 - 49151 are to be registered with IANA to prevent duplicating. They can be used for proprietary server processors or nay client process.

Dynamic Ports

The ports numbers from 49152 - 65535 are dynamic or ephemeral ports. It can be frequently used. Normally they are used by client process temporarily. The client process need not have a fixed port number. For example a client can access the server with client port number 50000. after terminating that connection, if the client need to make a connection with server again, the second time client can arbitrarily select port number 65004.