Chapter 9

Question 1

What is frame type identification

Answer 1

To differentiate different type of content in frame, a special area is allocated. This is called frame type identification.

Question 2

What is hardware addressing/physical addressing/mac addressing

Answer 2

We use hardware addressing to specify our destination. It means when a machine send a message, all other receives it. But all other machines should not spent time to identify is this message for them or not by using their CPU. Hardware address is always unique to its LAN.

Question 3

Does each station on network is assigned a numeric hardware/physical address.

Answer 3

Yes

Question 4

What is source address

Answer 4

Sender address

Question 5

What is LAN interface and packet filtering

Answer 5

Its a separate hardware from machine. When a frame receives to machine then LAN interface of that machine checks inside the frame and checks the destination address on incoming frame. If the physical address of that machine and destination address does not match then LAN interface discard that frame otherwise let it go to machine. This saves the processing time of CPU.

Question 6

What are address fields

Answer 6

Frame has 2 addresses. One is source address and one is destination address. These both are called address fields.

Question 7

What are the 3 techniques to assign unique hardware address to NIC (network interface card)

Answer 7

1. Static addressing
2. Configurable addressing
3. Dynamic addressing

Question 8

What is static addressing

Answer 8

Hardware manufacturer assigns permanent physical address to each network interface card.

Question 9

What is configurable addressing

Answer 9

Address can be set by end user either by manual (jumpers, switches) or electronically (software)

Question 10

What is dynamic addressing

Answer 10

Interface automatically assign physical address each time it is powered up.

Question 11

Which addressing scheme is most frequently used

Answer 11

Configurable addressing

Question 12

What is broadcasting

Answer 12

A sender something and all receivers on LAN receives a copy.

Question 13

What is broadcast address

Answer 13

The problem is broadcast concept is against LAN communication where NIC do packet filtering whereas broadcasting says every machine should receives a copy. To handle this each NIC has a separate area for broadcast called broadcast address.

Question 14

What is multi casting

Answer 14

The problem of receiving unintended messages again rises in broadcasting that what will happen, say, if 100 computers receives broadcast message and only 10 need it and 90 does not need it. NIC will allow to go and process broadcast message through broadcast address and CPU has to decide it. This is the same problem as we faced in LAN communication and used packet filtering. It solution is multi casting. In multi casting specific set of computer selects either they want to receives broadcast message or not.