A network can be simply defined as a group of computers and other devices connected in order to exchange data.
Each of the devices on the network can be thought of as a node; each node has a unique address, which is a numeric quantity.
Example: 204.160.241.98
There are two principle kinds of networks
Wide Area Networks (WANs) and Local Area Networks (LANs)
Wide Area Networks (WANs)
Local Area Networks (LANs)
Ethernet LANs – It is a broadcast communication based on a bus topology.
Token ring LANs – This is based on a ring topology.
FDDI LANs – It works based on the token ring mechanism where two rings flow in the opposite directions and use optical fiber.
Protocols –
OSI Layers
Physical layer –
Data link layer –
Network layer –
Transport layer –
Session layer –
Presentation layer –
Application layer –
TCP/IP Model
The TCP/IP Model –
Consists of only 4 layers they are:
Network layer
Internet layer
Transport layer
Application layer
Internet Protocol (IP) –
Internet protocol has main two functions, such as
→ It decomposes the initial information flow into packets of standardized size and then reassembles at the destination.
→ It also routes a packet through networks, from the source to the destination which is identified by its IP address.
→ Also the transmitted packets are not guaranteed to be delivered (datagram protocol).
→ Each datagram will have a header including IP address and port number of the destination.
→ Datagrams are then sent to selected gateways
→ E.g. IP routers, connected at the same time to the local network and to an IP service provider network.
Structure of an IP packet –
Transmission Control Protocol (TCP) –
→ TCP guarantees safe delivery, error detection, safe data transmission and assures that data is received in the correct order with help of IP.
→ It also requires that the computers communicating establish a connection (connection-oriented protocol) before sending the data.
User Datagram Protocol (UDP) –
→ Datagram protocols are built on top of IP which is useful for sending small size data.
→ It has the same packet-size limit (64Kb) as IP but allows for port number specification.
→ It provides 65,536 different ports and every machine has two sets of 65,536 ports which are specified one for TCP and the other for UDP.
→ Without any further verification, it provides support only for data transmission from one end to the other.
FTP (File Transfer Protocol) –
Telnet (Terminal Protocol) –
NNTP (Network News Transfer Protocol) –
SMTP (Simple Mail Transfer Protocol) –
SNMP (Simple Network Management Protocol) –
Recap
Networking
A network can be simply defined as a group of computers and other devices connected in order to exchange data.
There are two principle kinds of networks
Wide Area Networks (WANs) and Local Area Networks (LANs)
OSI Layers
Functions of data transmission through OSI layers
TCP/IP Model
Consists of only 4 layers they are:
Structure of an IP packet
TCP / UDP
Q.1 |
In which communication system there is no computer as such to transmit the data centrally? |
a) | Star |
b) | Ring |
c) | Complete |
d) | Multipoint |
Q.2 |
In which communication system every local computer is connected to another local computer? |
a) | Complete |
b) | Multipoint |
c) | Ring |
d) | Star |
Q.3 |
Which topology is called the point to point linked network? |
a) | Hybrid |
b) | Complete |
c) | Multipoint |
d) | Ring |
Q.4 |
In which topology is every computer given the control to decide its communication priorities? |
a) | Hybrid |
b) | Multipoint |
c) | Ring |
d) | Complete |
Q.5 |
Which topology is a combination of two or more topologies? |
a) | Multipoint |
b) | Bus |
c) | Complete |
d) | Hybrid |
Q.6 |
Which topology is also called the Bus topology? |
a) | Multipoint |
b) | Star |
c) | Complete |
d) | Hybrid |
Q.7 |
Which topology sets up a LAN? |
a) | Star |
b) | Multipoint |
c) | Ring |
d) | All of these |
Q.8 |
In which topology is every local computer connected to only one other computer? |
a) | Star |
b) | Ring |
c) | Hybrid |
d) | Complete |
Q.9 |
What is the advantage of Networking? |
a) | Sharing resources |
b) | Staying updated |
c) | Interaction has become better |
d) | All of these |
Q.10 |
What is the full form of PAN? |
a) | Project Area Network |
b) | Peripheral Area Network |
c) | Personal Area Network |
d) | Package Area Network |
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