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:
100ร10=1000100 \times 10 = 1000100ร10=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:
24ร10=24024 \times 10 = 24024ร10=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:
2โGbps500โMbps=4โseconds\frac{2 \, \text{Gbps}}{500 \, \text{Mbps}} = 4 \, \text{seconds}500Mbps2Gbpsโ=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:
20โMbpsร3600โsecondsร2โhours=144โGB20 \, \text{Mbps} \times 3600 \, \text{seconds} \times 2 \, \text{hours} = 144 \, \text{GB}20Mbpsร3600secondsร2hours=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:
48ร1โGbps=48โGbps48 \times 1 \, \text{Gbps} = 48 \, \text{Gbps}48ร1Gbps=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} = 25041000โ=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:
1โGbps=1ร109โbits per second1 \, \text{Gbps} = 1 \times 10^9 \, \text{bits per second}1Gbps=1ร109bits per second
1ร109โbits per secondร0.01โseconds=5,000โbits1 \times 10^9 \, \text{bits per second} \times 0.01 \, \text{seconds} = 5,000 \, \text{bits}1ร109bits per secondร0.01seconds=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:
10โMbps=10ร106โbits per second10 \, \text{Mbps} = 10 \times 10^6 \, \text{bits per second}10Mbps=10ร106bits per second.
Each packet is 1500 bytes =1500ร8โbits=12,000โbits= 1500 \times 8 \, \text{bits} = 12,000 \, \text{bits}=1500ร8bits=12,000bits.
Number of packets per second:
10ร106โbits12,000โbits per packet=800โpackets per second\frac{10 \times 10^6 \, \text{bits}}{12,000 \, \text{bits per packet}} = 800 \, \text{packets per second}12,000bits per packet10ร106bitsโ=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 = 4ร5โms=20โms4 \times 5 \, \text{ms} = 20 \, \text{ms}4ร5ms=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 = 10,000โpacketsร500โbytes=5,000,000โbytes10,000 \, \text{packets} \times 500 \, \text{bytes} = 5,000,000 \, \text{bytes}10,000packetsร500bytes=5,000,000bytes.
In kilobytes:
5,000,000โbytes1024=500โKB\frac{5,000,000 \, \text{bytes}}{1024} = 500 \, \text{KB}10245,000,000bytesโ=500KB.
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