ch 2

Question 1

why OSI has not dominated like TCP ?

Answer 1

1. TCP appeared earlier.
2. OSI is more complex and could result in heavy processing.

Question 2

what is the application layer?

Answer 2

provides the user interface and support and enable the user to connect to the network.

Question 3

what are the protocols of the application layer?

Answer 3

1. HTTP
2. FTP
3. TELENT
4. SMTP
5. DNS

Question 4

what is the presentation layer?

Answer 4

1. translate between two different encoding methods
2. Encryption: for privacy
3. compression: reduce the number of bits in contained in the information.

Question 5

what is the session layer?

Answer 5

1. dialogue control: allows two systems to enter a dialogue; either half or full duplex.
2. Synchronization: add a checkpoint into a stream of data.
   فتح و إغلاق السيشن وتحديد القناة

Question 6

what is the transport layer?

Answer 6

1. responsible for the delivery of the message from one process to another
2. handles the source-to-destination delivery of the message possibly across multiple networks.
3. performs error hand, ensures all data received in proper sequence, and if the data is missing resend it again.

Question 7

what are the protocols of the transport layer?

Answer 7

1. TCP
2. UDP

Question 8

what is the network layer?

Answer 8

1. responsible for creating the connection between the source and destination devices.
2. handles the reception of the message possibly across multiple networks

Question 9

what is the protocol used in the network layer?

Answer 9

IP

Question 10

what is the data link layer?

Answer 10

1. responsible for transmitting the datagram from one node to another.
2. makes the physical layer appears error free.
   a- framing: divde the stream of packet from the network layer into packets.
   b-physical addressing
   c- flow control
   d- error control
   e- prevent duplication.

Question 11

what is the physical layer?

Answer 11

1. establish the physical characteristics of the network e.g. cable
2. define the electrical characteristics of the network
3. transmit the binary data as electrical signals.