Interview questions

Question 1

what is the OSI model in networking?

Answer 1

OSI is a reference model which shows how applications communicate in a network, consist of 7 layers .

1. Physical (it sets up the bit streams across network)
2. Data link (sets up links across networks, deals with framing and MAC addresses)
3. network Layer (handles addressing and routing data)
4. Transport (used for end to end encryption communication. TCP UDP)
5. Session Layer (used for interhost communication)
6. Presentation (data representation and encryption
7. application (services that process data)

Question 2

explain the TCP/IP model

Answer 2

has 4 layers instead of 7

Network layer (data and physical)

Interntet layer (network)

Transport layer

Application layer (session, presentation and application)

Question 3

what is data encapsulation and deencapsulation

Answer 3

as data is passed from 1 layers of the OSI model, each layer adds a header containing protocol information specific to that layer

Headers are called PDU - protocol data unit

once the data has reached its destination, those PDUs are stripped away (de encapsulation)

Question 4

what is Ethernet and explain different cabling types?

Answer 4

ethernet is as suite of tecnologies which provide data link and physical specifications for controlling access to a shared network

Coax, twisted pain, fiber