Computer Network
Q71.
Two hosts are connected via a packet switch with 10^{7} bits per second links. Each link has a propagation delay of 20 microseconds. The switch begins forwarding a packet 35 microseconds after it receives the same. If 10000 bits of data are to be transmitted between the two hosts using a packet size of 5000 bits, the time elapsed between the transmission of the first bit of data and the reception of the last bit of the data in microseconds is____________.Q72.
Consider a network connecting two systems located 8000 kilometers apart. The bandwidth of the network is 500x10^{6} bits per second. The propagation speed of the media is 4x10^{6} meters per second. It is needed to design a Go-Back-N sliding window protocol for this network. The average packet size is 10^{7} bits. The network is to be used to its full capacity. Assume that processing delays at nodes are negligible. Then, the minimum size in bits of the sequence number field has to be ___________.Q73.
In a columnar transportation cipher, the plain text is "the tomato is a plant in the night shade family", keyword is "TOMATO". The cipher text isQ76.
What is one advantage of setting up a DMZ (Demilitarized Zone) with two firewalls?Q77.
In an RSA cryptosystem, the value of the public modulus parameter n is 3007. If it is also is known that \phi(n)=2880, where \phi() denotes Euler's Totient Function, then the prime factors of n which is greater than 50 is _________ .Q80.
In cryptography, the following uses transposition ciphers and the keyword is LAYER. Encrypt the following message. (Spaces are omitted during encrypton)WELCOME TO NETWORK SECURITY!