Addressing in Computer Network
Addressing means, giving a location of particular object right? why the addressing is needed in the computer network, and what are the addresses used are the topic that we are going to cover in this entire article. Addressing is needed, so that one device in the network can successfully transmit the information to another device located in remote site, anywhere in the network. We mainly going to explain about three major addressing in computer network they are logical addressing also called as IP addressing, Physical addressing also called as MAC address and port address (service address)
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1.IP Address
This are the unique identification number given to every computing devices connected to the internet so that each device can uniquely distinguished with each other entire the whole network, this address is called IP address it is 32 bit address, also called as logical address because it is not a address of particular hardware of your laptop, mobile or any other gadget, It is the logical address given to your devices by your ISP (Internet Service Provider)- from where you get the internet connectivity. We have clearly explained about all the private IP, Public IP in our other post click here.
2.Mac Address
It is also called as physical address because it is the unique number given to physical part of your laptop, mobile, computer and other gadgets. It is the address of NIC card Network Interface Card, also called as LAN card (Ethernet Card), MAC address can also be said as LAN address. It is the 48 bit address so that total of 2 to the power 48 address can be generated. This address is divided into six group each group contain one byte (8 bit) and each group is separated by middle score.
General Representation of MAC address:-
49-23-F9-CD-06-9B
this six byte are represented in hexadecimal notation. This address of adapter, that is MAC address is permanent can't be changed later.
Whenever you send data from one device to another device in the network there must be included a source host MAC address and Destination host MAC address as well as source IP and destination IP. Actually in the destination MAC address field physical address of next nearly connected devices or router in the network is assigned in this way data is reached to the receiver host of already known IP.
next article- private IP public IP concept clear click here.
General Representation of MAC address:-
49-23-F9-CD-06-9B
this six byte are represented in hexadecimal notation. This address of adapter, that is MAC address is permanent can't be changed later.
How the MAC address is managed
One interesting fact about MAC address is that, no two adapters have same MAC address, this might sounds surprising, adapters are manufactured in different country even by different company, How does the company manufacturing adapters in USA make sure that it is using different MAC address from a company manufacturing adapters in India. This all the management of physical address is done by IEEE. When a company want to manufacture a adapters, it purchase a chunk of block of physical address. IEEE gives a block of physical address to the company by fixing first 24 bit fixed as a vendor's ID and letting the company to create unique physical address for each adapters from remaining last 24 bit from the address block.
Whenever you send data from one device to another device in the network there must be included a source host MAC address and Destination host MAC address as well as source IP and destination IP. Actually in the destination MAC address field physical address of next nearly connected devices or router in the network is assigned in this way data is reached to the receiver host of already known IP.
3.Port address
Arriving the data at destination host is not a final objective of communication. Computer is device running multiple process at a same time so there must be a process to process communication. The message sent from particular process or application must be delivered to respective application or process in destination host. For example, computer A want to communicate with computer C with TELNET and at the same time computer A is communicating with computer C using FTP (File Transfer Protocol). To deliver the message of particular process to its respective process in destination, we need to distinguish the different process so here the port address is used to uniquely distinguished the process running in the same computer. So port address is address of process running on the computer. Example the default port for HTTP server listen to is 80 but it can be changed.
Multiplexing and Demultiplexing
Gathering the data from multiple application or process from sender wrapping them into the single header and send them as a whole to the intended receiver is called multiplexing. Demultiplexing is the process of delivering the information to the respected application according to the Port address.
Example: Suppose you are sending a message to your friend in both emo and whatsapp, both the sender and receiver have the app installed in their phones. While sending the message to your friend in emo, sending device must know the destination IP address of your friend's mobile and destination port address also the destination port address of whatsapp, now they are wrapped into the single header and send them as a single data to the receiver, this process is known as multiplexing and demultiplexing is unwrapping the received data, looking at the destination port address for each data and send them to the appropriate application or process.
next article- private IP public IP concept clear click here.
