In: Computer Science
Size of DNS response packet = 1000 bytes = 8000 bits
(a) Let's find the packet rate for each of the links.
For 30 Mbps link, packet rate = 30000000 / 8000 = 3750 packets per second
For 100 Mbps link, packet rate = 100000000 / 8000 = 12,500 packets per second
For 1 Gbps link, packet rate = 1000000000 / 8000 = 125,000 packets per second
(b) Size of DNS request packet to the intermediary = 60 bytes = 60 * 8 = 480 bits
Now let's find the bandwidth for each of these links.
For the 30 Mbps links, we had 3750 packets per second. Bandwidth = 3750 * 480 = 1.8 Mbps
For the 100 Mbps links, we had 12,500 packets per second. Bandwidth = 12,500 * 480 = 6 Mbps
For the 1 Gbps links, we had 125,000 packets per second. Bandwidth = 125,000 * 480 = 60 Mbps
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