GATE Networks 3

Question 1

In CSMA/CD, after the k-th collision, a station waits a random number of slot times chosen from [0, 2^k - 1]. This is called:

Accepted Answer

Binary exponential backoff

Answer

Binary exponential backoff doubles the contention window after each successive collision, reducing the probability of repeated collisions.

Question 2

Which layer of the OSI model is responsible for end-to-end error detection and flow control between hosts?

Accepted Answer

Transport layer

Answer

The transport layer (Layer 4) provides end-to-end reliable delivery, error detection, and flow control between communicating hosts.

Question 3

A network uses Go-Back-N ARQ with a window size of 4. If frame 3 is lost, which frames must be retransmitted?

Accepted Answer

Frames 3, 4, 5, and 6

Answer

In Go-Back-N, when frame 3 is lost, the receiver discards all subsequent frames; the sender must retransmit frame 3 and all frames sent after it within the window.

Question 4

Which protocol resolves an IP address to the corresponding MAC address on a local network?

Accepted Answer

ARP

Answer

ARP (Address Resolution Protocol) broadcasts an IP address query and receives the corresponding MAC address from the owning host.

Question 5

The OSPF routing protocol is based on which algorithm?

Accepted Answer

Link state

Answer

OSPF (Open Shortest Path First) is a link-state protocol where each router maintains a complete topology map and runs Dijkstra's algorithm locally.

(GATE) Graduate Aptitude Test in Engineering Practice Test

(GATE) Graduate Aptitude Test in Engineering Practice Test

GATE Networks 3