Computer Network GATE CS and IT previous year questions with Answer
Ques 21 Gate 2017 Set-1
In a RSA cryptosystem a particular A uses two prime numbers p = 13 and q =17 to generate her public and private keys. If the public key of A is 35. Then the private key of A is ____________.
11 is the correct answer.
Ques 22 Gate 2017 Set-1
Consider a TCP client and a TCP server running on two different machines. After completing data transfer, the TCP client calls close to terminate the connection and a FIN segment is sent to the TCP server. Server-side TCP responds by sending an ACK which is received by the client-side TCP. As per the TCP connection state diagram(RFC 793), in which state does the client side TCP connection wait for the FIN from the server-side TCP?
Ques 23 Gate 2017 Set-1
A computer network uses polynomial over GF(2) for error checking with 8 bits as information bits and uses x3 + x + 1 as the generator polynomial to generate the check bits. In this network, the message 01011011 is transmitted as
Ques 24 Gate 2017 Set-1
A sender S sends a message m to receiver R, which is digitally signed by S with its private key. In this scenario, one or more of the following security violations can take place.
(II) A third party attacker can launch a birthday attack to replace m with a fraudulent message.
(III) R can launch a birthday attack to replace m with a fraudulent message.
Ques 25 Gate 2016 Set-2
Consider a 128×103 bits/second satellite communication link with one-way propagation delay of 150 milliseconds. Selective retransmission (repeat) protocol is used on this link to send data with a frame size of 1 kilobyte. Neglect the transmission time of acknowledgment. The minimum number of bits required for the sequence number field to achieve 100% utilization is ___________
a is the correct answer.
Ques 26 Gate 2016 Set-2
A network has a data transmission bandwidth of 20 × 106 bits per second. It uses CSMA/CD in the MAC layer. The maximum signal propagation time from one node to another node is 40 microseconds. The minimum size of a frame in the network is _________
a is the correct answer.
Ques 27 Gate 2016 Set-2
For the IEEE 802.11 MAC protocol for wireless communication, which of the following statements is/are TRUE?
I. At least three non-overlapping channels are
available for transmissions.
II. The RTS-CTS mechanism is used for collision detection.
III. Unicast frames are ACKed.
Ques 28 Gate 2016 Set-2
Identify the correct sequence in which the following packets are transmitted on the network by a host when a browser requests a webpage from a remote server, assuming that the host has just been restarted.
Ques 29 Gate 2016 Set-2
In an Ethernet local area network, which one of the following statements is TRUE ?
Ques 30 Gate 2016 Set-2
Anarkali digitally signs a message and sends it to Salim. Verification of the signature by Salim requires