1. If a router forwards 100 packets per second to 5 different destinations, how many packets will be forwarded to each destination in 10 seconds?
a) 100
b) 500
c) 1000
d) 2000
Answer: c) 1000
Explanation:
For 5 destinations, each will receive 100 packets/second. In 10 seconds, each destination will receive:
100×10=1000100 \times 10 = 1000100×10=1000 packets.
2. A switch has 24 ports. If each port is transmitting 10 Mbps, what is the total bandwidth required for the switch?
a) 10 Mbps
b) 24 Mbps
c) 240 Mbps
d) 2400 Mbps
Answer: c) 240 Mbps
Explanation:
Total bandwidth is the sum of bandwidth of all ports:
24×10=24024 \times 10 = 24024×10=240 Mbps.
3. A router is forwarding 2 Gbps of data. If it can process 500 Mbps at a time, how many seconds will it take to process the entire 2 Gbps data?
a) 2 seconds
b) 4 seconds
c) 6 seconds
d) 8 seconds
Answer: b) 4 seconds
Explanation:
Time to process data:
2 Gbps500 Mbps=4 seconds\frac{2 \, \text{Gbps}}{500 \, \text{Mbps}} = 4 \, \text{seconds}500Mbps2Gbps=4seconds.
4. A modem can transmit 20 Mbps over a cable. How much data will it transmit in 2 hours?
a) 72 GB
b) 144 GB
c) 48 GB
d) 1440 MB
Answer: b) 144 GB
Explanation:
Data transmitted in 2 hours:
20 Mbps×3600 seconds×2 hours=144 GB20 \, \text{Mbps} \times 3600 \, \text{seconds} \times 2 \, \text{hours} = 144 \, \text{GB}20Mbps×3600seconds×2hours=144GB.
5. If a network switch has 48 ports and each port supports a speed of 1 Gbps, what is the maximum possible throughput of the switch?
a) 48 Gbps
b) 96 Gbps
c) 24 Gbps
d) 1 Gbps
Answer: b) 96 Gbps
Explanation:
Total throughput:
48×1 Gbps=48 Gbps48 \times 1 \, \text{Gbps} = 48 \, \text{Gbps}48×1Gbps=48Gbps.
6. A router receives 1000 packets every second and forwards each packet to one of 4 different networks. If each network requires 2 seconds for the router to process its traffic, how many seconds will it take for the router to process all packets?
a) 1000 seconds
b) 250 seconds
c) 500 seconds
d) 2000 seconds
Answer: b) 250 seconds
Explanation:
The router processes packets at the rate of 1000 packets/second. It needs to process them for 4 networks, each requiring 2 seconds:
10004=250\frac{1000}{4} = 25041000=250 seconds.
7. If a switch operates at 1 Gbps and has a latency of 5 ms, how much data will pass through the switch in 10 milliseconds?
a) 10,000 bits
b) 5,000 bits
c) 50,000 bits
d) 100,000 bits
Answer: b) 5,000 bits
Explanation:
Data in 10 ms at 1 Gbps:
1 Gbps=1×109 bits per second1 \, \text{Gbps} = 1 \times 10^9 \, \text{bits per second}1Gbps=1×109bits per second
1×109 bits per second×0.01 seconds=5,000 bits1 \times 10^9 \, \text{bits per second} \times 0.01 \, \text{seconds} = 5,000 \, \text{bits}1×109bits per second×0.01seconds=5,000bits.
8. A hub transmits data at 10 Mbps, and the data is divided into 1500-byte packets. How many packets can be transmitted in 1 second?
a) 800
b) 1000
c) 1500
d) 2000
Answer: a) 800
Explanation:
First, convert 10 Mbps to bits per second:
10 Mbps=10×106 bits per second10 \, \text{Mbps} = 10 \times 10^6 \, \text{bits per second}10Mbps=10×106bits per second.
Each packet is 1500 bytes =1500×8 bits=12,000 bits= 1500 \times 8 \, \text{bits} = 12,000 \, \text{bits}=1500×8bits=12,000bits.
Number of packets per second:
10×106 bits12,000 bits per packet=800 packets per second\frac{10 \times 10^6 \, \text{bits}}{12,000 \, \text{bits per packet}} = 800 \, \text{packets per second}12,000bits per packet10×106bits=800packets per second.
9. If a network uses 4 routers, and each router has a delay of 5 ms, what will be the total delay for a packet to travel through all routers?
a) 15 ms
b) 20 ms
c) 25 ms
d) 30 ms
Answer: c) 25 ms
Explanation:
Total delay = 4×5 ms=20 ms4 \times 5 \, \text{ms} = 20 \, \text{ms}4×5ms=20ms.
10. A router forwards 10,000 data packets every second. If each packet is 500 bytes in size, how many kilobytes of data does the router forward every second?
a) 500 KB
b) 400 KB
c) 1 MB
d) 5 MB
Answer: a) 500 KB
Explanation:
Total data forwarded = 10,000 packets×500 bytes=5,000,000 bytes10,000 \, \text{packets} \times 500 \, \text{bytes} = 5,000,000 \, \text{bytes}10,000packets×500bytes=5,000,000bytes.
In kilobytes:
5,000,000 bytes1024=500 KB\frac{5,000,000 \, \text{bytes}}{1024} = 500 \, \text{KB}10245,000,000bytes=500KB.
