Reference no: EM131549330

Part 1: A hard disk has four surfaces (that's top and bottom of two platters). Each track has 2,048 sectors and there are 131,072 (2¹⁷) tracks per surface. A block holds 512 bytes. The disk is not "zoned." What is the total capacity of this disk? Show your work. (Hint: what is the relationship between blocks and sectors? Another hint: All of the numbers given are powers of two.)

Part 2: Given the disk in Part 1, how much data can be accessed without moving the disk heads. (That, is, what is the capacity of one cylinder?)

Part 3: Information technology managers use RAID arrays to guard against loss of data in case of physical disk failure. Modern disk drives now have sizes in terabytes. What effect does this have on the reliability of RAID arrays? (Hint: What happens when a disk fails? How are data from the failed disk recovered, and how long does that take?)

Part 4: Breaking messages to be sent over a communication facility into packets introduces overhead, a disadvantage. Name and briefly describe three advantages of packet-switched communications.

Part 5: Explain what the ARP protocol does and how it works. (You need about a paragraph of detail; a single sentence will not do.)

In a separate paragraph, tell why the ARP protocol is needed; that is, why is the information provided by ARP even needed at all.

Part 6: The IP protocol (and UDP) are called "connectionless" and "unreliable." Describe what those two words mean in the context of data communications.

Part 7: What is an Ethernet collision? Explain the process by which Ethernet recovers from a collision.

Part 8: Explain how RAID can protect against disk hardware failure. (You need about a paragraph of detail; a single sentence will not do.)

Part 9: Explain how collisions are avoided in modern Ethernet network design. (You need about a paragraph of detail; a single sentence will not do.)

Part 10: Explain how an Ethernet switch determines to which port to forward an incoming packet. Your answer must cover both the case of a destination that has previously made a transmission and one that has not.