Unit Three Objectives CSCI 361 Introduction to Computer Networks Tobin Maginnis Updated: 19-Mar-08 Computer Networks, 4th ed - Chapter 3 - The Datalink Layer - A. S. Tanenbaum 0)Define a "UART" and describe the six steps of character reception. http://en.wikipedia.org/wiki/Uart 1)Define framing as an error control strategy and give its design tradeoff. 2)Explain why timing is too inefficient as an error control tool. 3)Describe character count framing and give its design weakness. 4)Define in-band signaling and describe two examples of frame stuffing. 5)Describe four possible ways a data frame could be lost. 6)Describe two type of error detection methods and give the tradeoff between two types of error correction methods. 7)Give the four fields of a frame explaining what is missing and why. 8)Describe the four steps in the utopia sender1 or receiver1 procedures. 9)Contrast a "delayed" protocol versus an asynchronous (stop-and-wait) protocol. 10)Explain how simple frame retransmission based on an acknowledge character or time-out condition would still allow errors to occur. 11)Explain why a modulo 2 sequence number is adequate to remove the error in protocol 2, the stop-and-wait protocol. 12)Describe the three differences between protocol 2 (stop-and-wait) and protocol 3 (PAR) and explain the effect of premature time-outs on the PAR protocol. 13)Give the four possible scenarios of PAR frame transmission and reception. 14)Define "piggy-backing" and give three advantages & one disadvantage for its use. 15)Define "Sliding Window" and describe the wire-like "essence" of all sliding window protocols. 16)Describe the three differences between the PAR and sliding window protocols. 17)Describe how protocol four, the sliding window protocol, can survive early-frame time-out problem and explain how it still has a weakness which can lead to doubling network traffic. 18)Explain how the combination of a long transit time, high bandwidth, and short frames create extreme inefficiency. 19)Define "pipelining" and give two ways of dealing with errors and give the design tradeoff. 20)Explain why sequence numbers must be two times the buffer size in sliding window protocols. 21)Contrast "SDLC," "ADCCP," "HDLC," "LAP," and "LAPB", and describe the contents of the six fields in a typical bit-oriented frame (11 parts). Omit)Describe the two ways the P/F is employed in a bit-oriented frame. Omit)Describe the three types of bit-oriented control fields. Omit)Describe the four types of bit-oriented supervisory sub-fields. Omit)Contrast "SNRM," "SABM," "SABME," and "SNRME." 26)Give an overview of PPP (five parts). Computer Networks, 4th ed - Chapter 4 - The Medium Access Sublayer 27)Define "Ethernet," describe the CSMA/CD protocol, and describe "binary exponential backoff." Omit)Describe four types of Ethernet cabling, in terms of segment lengths, number of stations, and today's use. Omit)In terms of Ethernet, define "reflection," "termination," and "connector configuration" and explain why these implementation issues are not found in fiber-optic Ethernet adapters. Omit)Support or refute the idea that we should use high speed point-to-point connections among routers instead of wasting bandwidth simulating a broadcast network. (Consider 4/16 Mbs token ring for your answer.) 31)Give a strategy to run a LAN through a building. (wiring closets & repeaters) 32)Define "Manchester Encoding" and describe its role relative to Nyquist. 33)Describe an Ethernet frame format and explain how it may or may not interact with the length of the broadcast medium. http://en.wikipedia.org/wiki/Jumbo_Frame Omit)Describe the operation of "collision domains" in an Ethernet switch. 35)Describe the modifications to allow 100 Mbs and 1 Gbs Ethernet (5 parts). http://en.wikipedia.org/wiki/IEEE_802.3 http://en.wikipedia.org/wiki/Gigabit_ethernet http://en.wikipedia.org/wiki/10_Gigabit_Ethernet http://en.wikipedia.org/wiki/100_Gigabit_Ethernet 36)List five justifications for employing a LAN bridge. Omit)List three incompatibilities among LANs and the resulting design constraints for the bridge builder and LAN manager. 38)Define bridge, describe the three "routing" steps employed in a "transparent" LAN bridge, and explain why or why not this is really routing. 39)Explain why spanning trees are required in LAN (three parts) and list the three steps a transparent bridge employs to construct a spanning tree.