1. For a 10Mbps Ethernet link, if the length of the packet is 32bits, the transmission delay is ____________ (in microseconds)
a) 3.2
b) 32
c) 0.32
d) 320
Explanation: Transmission rate = length / transmission rate = 32/10 = 3.2 microseconds.
2. The time required to examine the packet’s header and determine where to direct the packet is part of __________
a) Processing delay
b) Queuing delay
c) Transmission delay
d) Propagation delay
Explanation: Processing delay is induced at a router’s or other network processor’s end in the path of the packet and is caused by the time taken by the processor to examine the packet’s header to decide the further path of the packet.
3. Given L = number of bits in the packet, a = average rate and R = transmission rate. The Traffic intensity in the network is given by ____________
a) La/R
b) LR/a
c) R/La
d) Ra/L
Explanation: Traffic Intensity = (Number of bits in packet * Average Transmission rate)/Current Transmission rate.
4. In the transfer of file between server and client, if the transmission rates along the path is 10Mbps, 20Mbps, 30Mbps, 40Mbps. The throughput is usually ___________
a) 20Mbps
b) 10Mbps
c) 40Mbps
d) 50Mbps
Explanation: The throughput is generally the transmission rate of bottleneck link.
5. If end to end delay is given by dend-end = N(dproc + dtrans + dprop) is a non congested network. The number of routers between source and destination is?
a) N/2
b) N
c) N-1
d) 2N
Explanation: In the equation N (dproc + dtrans + dprop), N is the number of checkpoints/stops that the packet makes as it reaches the destination. The stops are made at each router and the final destination node. Now, since N = number of routers + final node, then number of routers = N – final node. As we know, there is only 1 final node in a path, thus, number of routers = N – 1. Suppose, There is a path A->R1->R2->B for a packet where A is the source node, B is the final node and R1 and R2 are routers. The total delay would be given by N (dproc + dtrans + dprop) where N = 3, since the packet would stop at R1, R2 and B. The number of routers here are 2, and (N – 1) is also 2.
6. The total nodal delay is given by ____________
a) dnodal = dproc – dqueue + dtrans + dprop
b) dnodal = dproc + dtrans – dqueue
c) dnodal = dproc + dqueue + dtrans + dprop
d) dnodal = dproc + dqueue – dtrans – dprop
Explanation: The total node-to-node delay, that is, nodal delay is the sum of all, the processing delay, queuing delay, transmission delay and propagation delay. Ideally, the nodal delay must be low as possible for a better Quality of Service of the network.
7. In a network, If P is the only packet being transmitted and there was no earlier transmission, which of the following delays could be zero?
a) Propagation delay
b) Queuing delay
c) Transmission delay
d) Processing delay
Explanation: Since there is no other packet to be transmitted, there is no need for a queue. Therefore, the delay caused due to the queuing would be none i.e. 0.
8. Transmission delay does not depend on _____________
a) Packet length
b) Distance between the routers
c) Transmission rate
d) Bandwidth of medium
Explanation: Transmission delay = packet length / transmission rate. The transmission rate depends upon the bandwidth of the medium.
9. Propagation delay depends on ___________
a) Packet length
b) Transmission rate
c) Distance between the routers
d) Speed of the CPU
Explanation: Propagation delay is caused when the packet is in its electric signal form and is travelling through a medium (a wire or a electromagnetic wave). Propagation delay is the time it takes a bit to propagate from one router to the next. If the distance between the routers is increased, it will take longer time to propagate, that is, there would be more propagation delay.
10. The attacker using a network of compromised devices is known as _____________
a) Internet
b) Botnet
c) Telnet
d) D-net
Explanation: Botnet is a network of compromised devices used by the attacker without the owner’s knowledge to perform unethical activities such as spamming. The attacker usually uses the least secure devices to create the botnet.
Why Computer Network ?
The Need for Speed
Ever felt like your Wi-Fi is on a coffee break when you're in the middle of binge-watching your favorite show? Blame it on delays! In the universe of computer networks, delays are the mischievous elves that sneak in and slow down your data traffic.
Imagine your data as a speedy delivery guy on a scooter. Delays are like unexpected speed bumps on his route, causing him to hit the brakes. Buffering screens and lag in online games are just a reminder that even the digital world has its traffic jams.
Loss, the Invisible Bandit
Now, let's talk about losses – the ninja assassins of the digital realm. Unlike delays, losses are stealthy. They silently swipe away bits of your data in the dark corners of the internet. It's like sending a postcard to your grandma, and somewhere along the way, the postman decides to keep it as a souvenir.
Computer networks use a nifty system to detect and recover from losses, like a superhero retrieving stolen goods. But sometimes, a few bits decide to take a vacation without leaving a forwarding address.
The Connection Conundrum
Ever wondered why your video call freezes at the most awkward moments? That's the connection conundrum at play. When delays and losses gang up, it's like a cosmic conspiracy to make your virtual presence a tad glitchy.
Computer networks rely on protocols and algorithms to keep the data dance smooth. But, hey, even the best dancers can step on each other's toes once in a while.
Remember, in the world of computer networks, understanding delays and losses is the key to a glitch-free digital adventure. Until next time, happy networking!