COMPLETE TEST BANK: computer networking:
a top-down approach 7th edition by james
kurose
,COMPUTER NETWORKING: A TOP-DOWN APPROACH, 7TH
EDITION
SOLUTIONS TO REVIEW QUESTIONS AND PROBLEMS
VERSION DATE: DECEMBER 2016
THIS DOCUMENT CONTAINS THE SOLUTIONS TO REVIEW QUESTIONS AND PROBLEMS FOR THE 7TH
EDITION OF COMPUTER NETWORKING: A TOP-DOWN APPROACH BY JIM KUROSE AND KEITH ROSS.
THESE SOLUTIONS ARE BEING MADE AVAILABLE TO INSTRUCTORS ONLY. PLEASE DO NOT COPY OR
DISTRIBUTE THIS DOCUMENT TO OTHERS (EVEN OTHER INSTRUCTORS). PLEASE DO NOT POST ANY
SOLUTIONS ON A PUBLICLY-AVAILABLE WEB SITE. WE’LL BE HAPPY TO PROVIDE A COPY (UP-TO-DATE)
OF THIS SOLUTION MANUAL OURSELVES TO ANYONE WHO ASKS.
ACKNOWLEDGMENTS: OVER THE YEARS, SEVERAL STUDENTS AND COLLEAGUES HAVE HELPED US
PREPARE THIS SOLUTIONS MANUAL. SPECIAL THANKS GOES TO HONGGANG ZHANG, RAKESH KUMAR,
PRITHULA DHUNGEL, AND VIJAY ANNAPUREDDY. ALSO THANKS TO ALL THE READERS WHO HAVE MADE
SUGGESTIONS AND CORRECTED ERRORS.
,CHAPTER 1 REVIEW QUESTIONS
1. THERE IS NO DIFFERENCE. THROUGHOUT THIS TEXT, THE WORDS “HOST” AND “END SYSTEM”
ARE USED INTERCHANGEABLY. END SYSTEMS INCLUDE PCS, WORKSTATIONS, WEB SERVERS, MAIL
SERVERS, PDAS, INTERNET-CONNECTED GAME CONSOLES, ETC.
2. FROM WIKIPEDIA: DIPLOMATIC PROTOCOL IS COMMONLY DESCRIBED AS A SET OF
INTERNATIONAL COURTESY RULES. THESE WELL-ESTABLISHED AND TIME-HONORED RULES HAVE MADE
IT EASIER FOR NATIONS AND PEOPLE TO LIVE AND WORK TOGETHER. PART OF PROTOCOL HAS ALWAYS
BEEN THE ACKNOWLEDGMENT OF THE HIERARCHICAL STANDING OF ALL PRESENT. PROTOCOL RULES
ARE BASED ON THE PRINCIPLES OF CIVILITY.
3. STANDARDS ARE IMPORTANT FOR PROTOCOLS SO THAT PEOPLE CAN CREATE NETWORKING
SYSTEMS AND PRODUCTS THAT INTEROPERATE.
4. 1. DIAL-UP MODEM OVER TELEPHONE LINE: HOME; 2. DSL OVER TELEPHONE LINE: HOME OR
SMALL OFFICE; 3. CABLE TO HFC: HOME; 4. 100 MBPS SWITCHED ETHERNET: ENTERPRISE; 5. WIFI
(802.11): HOME AND ENTERPRISE: 6. 3G AND 4G: WIDE-AREA WIRELESS.
5. HFC BANDWIDTH IS SHARED AMONG THE USERS. ON THE DOWNSTREAM CHANNEL, ALL
PACKETS EMANATE FROM A SINGLE SOURCE, NAMELY, THE HEAD END. THUS, THERE ARE NO
COLLISIONS IN THE DOWNSTREAM CHANNEL.
6. IN MOST AMERICAN CITIES, THE CURRENT POSSIBILITIES INCLUDE: DIAL-UP; DSL; CABLE
MODEM; FIBER-TO-THE-HOME.
7. ETHERNET LANS HAVE TRANSMISSION RATES OF 10 MBPS, 100 MBPS, 1 GBPS AND 10 GBPS.
8. TODAY, ETHERNET MOST COMMONLY RUNS OVER TWISTED-PAIR COPPER WIRE. IT ALSO CAN
RUN OVER FIBERS OPTIC LINKS.
9. DIAL UP MODEMS: UP TO 56 KBPS, BANDWIDTH IS DEDICATED; ADSL: UP TO 24 MBPS
DOWNSTREAM AND 2.5 MBPS UPSTREAM, BANDWIDTH IS DEDICATED; HFC, RATES UP TO 42.8 MBPS
AND UPSTREAM RATES OF UP TO 30.7 MBPS, BANDWIDTH IS SHARED. FTTH: 2-10MBPS UPLOAD; 10-20
MBPS DOWNLOAD; BANDWIDTH IS NOT SHARED.
10. THERE ARE TWO POPULAR WIRELESS INTERNET ACCESS TECHNOLOGIES TODAY:
, A) WIFI (802.11) IN A WIRELESS LAN, WIRELESS USERS TRANSMIT/RECEIVE PACKETS TO/FROM AN
BASE STATION (I.E., WIRELESS ACCESS POINT) WITHIN A RADIUS OF FEW TENS OF METERS. THE BASE
STATION IS TYPICALLY CONNECTED TO THE WIRED INTERNET AND THUS SERVES TO CONNECT WIRELESS
USERS TO THE WIRED NETWORK.
B) 3G AND 4G WIDE-AREA WIRELESS ACCESS NETWORKS. IN THESE SYSTEMS, PACKETS ARE
TRANSMITTED OVER THE SAME WIRELESS INFRASTRUCTURE USED FOR CELLULAR TELEPHONY, WITH
THE
BASE STATION THUS BEING MANAGED BY A TELECOMMUNICATIONS PROVIDER. THIS PROVIDES
WIRELESS ACCESS TO USERS WITHIN A RADIUS OF TENS OF KILOMETERS OF THE BASE STATION.
11. AT TIME T0 THE SENDING HOST BEGINS TO TRANSMIT. AT TIME T1 = L/R1, THE SENDING HOST
COMPLETES TRANSMISSION AND THE ENTIRE PACKET IS RECEIVED AT THE ROUTER (NO PROPAGATION
DELAY). BECAUSE THE ROUTER HAS THE ENTIRE PACKET AT TIME T1, IT CAN BEGIN TO TRANSMIT THE
PACKET TO THE RECEIVING HOST AT TIME T1. AT TIME T2 = T1 + L/R2, THE ROUTER COMPLETES
TRANSMISSION AND THE ENTIRE PACKET IS RECEIVED AT THE RECEIVING HOST (AGAIN, NO
PROPAGATION DELAY). THUS, THE END-TO-END DELAY IS L/R1 + L/R2.
12. A CIRCUIT-SWITCHED NETWORK CAN GUARANTEE A CERTAIN AMOUNT OF END-TO-END
BANDWIDTH FOR THE DURATION OF A CALL. MOST PACKET-SWITCHED NETWORKS TODAY (INCLUDING
THE INTERNET) CANNOT MAKE ANY END-TO-END GUARANTEES FOR BANDWIDTH. FDM REQUIRES
SOPHISTICATED ANALOG HARDWARE TO SHIFT SIGNAL INTO APPROPRIATE FREQUENCY BANDS.
13. A) 2 USERS CAN BE SUPPORTED BECAUSE EACH USER REQUIRES HALF OF THE LINK BANDWIDTH.
B) SINCE EACH USER REQUIRES 1MBPS WHEN TRANSMITTING, IF TWO OR FEWER USERS
TRANSMIT SIMULTANEOUSLY, A MAXIMUM OF 2MBPS WILL BE REQUIRED. SINCE THE AVAILABLE
BANDWIDTH OF THE SHARED LINK IS 2MBPS, THERE WILL BE NO QUEUING DELAY BEFORE THE LINK.
WHEREAS, IF THREE USERS TRANSMIT SIMULTANEOUSLY, THE BANDWIDTH REQUIRED WILL BE 3MBPS
WHICH IS MORE THAN THE AVAILABLE BANDWIDTH OF THE SHARED LINK. IN THIS CASE, THERE WILL BE
QUEUING DELAY BEFORE THE LINK.
C) PROBABILITY THAT A GIVEN USER IS TRANSMITTING = 0.2
a top-down approach 7th edition by james
kurose
,COMPUTER NETWORKING: A TOP-DOWN APPROACH, 7TH
EDITION
SOLUTIONS TO REVIEW QUESTIONS AND PROBLEMS
VERSION DATE: DECEMBER 2016
THIS DOCUMENT CONTAINS THE SOLUTIONS TO REVIEW QUESTIONS AND PROBLEMS FOR THE 7TH
EDITION OF COMPUTER NETWORKING: A TOP-DOWN APPROACH BY JIM KUROSE AND KEITH ROSS.
THESE SOLUTIONS ARE BEING MADE AVAILABLE TO INSTRUCTORS ONLY. PLEASE DO NOT COPY OR
DISTRIBUTE THIS DOCUMENT TO OTHERS (EVEN OTHER INSTRUCTORS). PLEASE DO NOT POST ANY
SOLUTIONS ON A PUBLICLY-AVAILABLE WEB SITE. WE’LL BE HAPPY TO PROVIDE A COPY (UP-TO-DATE)
OF THIS SOLUTION MANUAL OURSELVES TO ANYONE WHO ASKS.
ACKNOWLEDGMENTS: OVER THE YEARS, SEVERAL STUDENTS AND COLLEAGUES HAVE HELPED US
PREPARE THIS SOLUTIONS MANUAL. SPECIAL THANKS GOES TO HONGGANG ZHANG, RAKESH KUMAR,
PRITHULA DHUNGEL, AND VIJAY ANNAPUREDDY. ALSO THANKS TO ALL THE READERS WHO HAVE MADE
SUGGESTIONS AND CORRECTED ERRORS.
,CHAPTER 1 REVIEW QUESTIONS
1. THERE IS NO DIFFERENCE. THROUGHOUT THIS TEXT, THE WORDS “HOST” AND “END SYSTEM”
ARE USED INTERCHANGEABLY. END SYSTEMS INCLUDE PCS, WORKSTATIONS, WEB SERVERS, MAIL
SERVERS, PDAS, INTERNET-CONNECTED GAME CONSOLES, ETC.
2. FROM WIKIPEDIA: DIPLOMATIC PROTOCOL IS COMMONLY DESCRIBED AS A SET OF
INTERNATIONAL COURTESY RULES. THESE WELL-ESTABLISHED AND TIME-HONORED RULES HAVE MADE
IT EASIER FOR NATIONS AND PEOPLE TO LIVE AND WORK TOGETHER. PART OF PROTOCOL HAS ALWAYS
BEEN THE ACKNOWLEDGMENT OF THE HIERARCHICAL STANDING OF ALL PRESENT. PROTOCOL RULES
ARE BASED ON THE PRINCIPLES OF CIVILITY.
3. STANDARDS ARE IMPORTANT FOR PROTOCOLS SO THAT PEOPLE CAN CREATE NETWORKING
SYSTEMS AND PRODUCTS THAT INTEROPERATE.
4. 1. DIAL-UP MODEM OVER TELEPHONE LINE: HOME; 2. DSL OVER TELEPHONE LINE: HOME OR
SMALL OFFICE; 3. CABLE TO HFC: HOME; 4. 100 MBPS SWITCHED ETHERNET: ENTERPRISE; 5. WIFI
(802.11): HOME AND ENTERPRISE: 6. 3G AND 4G: WIDE-AREA WIRELESS.
5. HFC BANDWIDTH IS SHARED AMONG THE USERS. ON THE DOWNSTREAM CHANNEL, ALL
PACKETS EMANATE FROM A SINGLE SOURCE, NAMELY, THE HEAD END. THUS, THERE ARE NO
COLLISIONS IN THE DOWNSTREAM CHANNEL.
6. IN MOST AMERICAN CITIES, THE CURRENT POSSIBILITIES INCLUDE: DIAL-UP; DSL; CABLE
MODEM; FIBER-TO-THE-HOME.
7. ETHERNET LANS HAVE TRANSMISSION RATES OF 10 MBPS, 100 MBPS, 1 GBPS AND 10 GBPS.
8. TODAY, ETHERNET MOST COMMONLY RUNS OVER TWISTED-PAIR COPPER WIRE. IT ALSO CAN
RUN OVER FIBERS OPTIC LINKS.
9. DIAL UP MODEMS: UP TO 56 KBPS, BANDWIDTH IS DEDICATED; ADSL: UP TO 24 MBPS
DOWNSTREAM AND 2.5 MBPS UPSTREAM, BANDWIDTH IS DEDICATED; HFC, RATES UP TO 42.8 MBPS
AND UPSTREAM RATES OF UP TO 30.7 MBPS, BANDWIDTH IS SHARED. FTTH: 2-10MBPS UPLOAD; 10-20
MBPS DOWNLOAD; BANDWIDTH IS NOT SHARED.
10. THERE ARE TWO POPULAR WIRELESS INTERNET ACCESS TECHNOLOGIES TODAY:
, A) WIFI (802.11) IN A WIRELESS LAN, WIRELESS USERS TRANSMIT/RECEIVE PACKETS TO/FROM AN
BASE STATION (I.E., WIRELESS ACCESS POINT) WITHIN A RADIUS OF FEW TENS OF METERS. THE BASE
STATION IS TYPICALLY CONNECTED TO THE WIRED INTERNET AND THUS SERVES TO CONNECT WIRELESS
USERS TO THE WIRED NETWORK.
B) 3G AND 4G WIDE-AREA WIRELESS ACCESS NETWORKS. IN THESE SYSTEMS, PACKETS ARE
TRANSMITTED OVER THE SAME WIRELESS INFRASTRUCTURE USED FOR CELLULAR TELEPHONY, WITH
THE
BASE STATION THUS BEING MANAGED BY A TELECOMMUNICATIONS PROVIDER. THIS PROVIDES
WIRELESS ACCESS TO USERS WITHIN A RADIUS OF TENS OF KILOMETERS OF THE BASE STATION.
11. AT TIME T0 THE SENDING HOST BEGINS TO TRANSMIT. AT TIME T1 = L/R1, THE SENDING HOST
COMPLETES TRANSMISSION AND THE ENTIRE PACKET IS RECEIVED AT THE ROUTER (NO PROPAGATION
DELAY). BECAUSE THE ROUTER HAS THE ENTIRE PACKET AT TIME T1, IT CAN BEGIN TO TRANSMIT THE
PACKET TO THE RECEIVING HOST AT TIME T1. AT TIME T2 = T1 + L/R2, THE ROUTER COMPLETES
TRANSMISSION AND THE ENTIRE PACKET IS RECEIVED AT THE RECEIVING HOST (AGAIN, NO
PROPAGATION DELAY). THUS, THE END-TO-END DELAY IS L/R1 + L/R2.
12. A CIRCUIT-SWITCHED NETWORK CAN GUARANTEE A CERTAIN AMOUNT OF END-TO-END
BANDWIDTH FOR THE DURATION OF A CALL. MOST PACKET-SWITCHED NETWORKS TODAY (INCLUDING
THE INTERNET) CANNOT MAKE ANY END-TO-END GUARANTEES FOR BANDWIDTH. FDM REQUIRES
SOPHISTICATED ANALOG HARDWARE TO SHIFT SIGNAL INTO APPROPRIATE FREQUENCY BANDS.
13. A) 2 USERS CAN BE SUPPORTED BECAUSE EACH USER REQUIRES HALF OF THE LINK BANDWIDTH.
B) SINCE EACH USER REQUIRES 1MBPS WHEN TRANSMITTING, IF TWO OR FEWER USERS
TRANSMIT SIMULTANEOUSLY, A MAXIMUM OF 2MBPS WILL BE REQUIRED. SINCE THE AVAILABLE
BANDWIDTH OF THE SHARED LINK IS 2MBPS, THERE WILL BE NO QUEUING DELAY BEFORE THE LINK.
WHEREAS, IF THREE USERS TRANSMIT SIMULTANEOUSLY, THE BANDWIDTH REQUIRED WILL BE 3MBPS
WHICH IS MORE THAN THE AVAILABLE BANDWIDTH OF THE SHARED LINK. IN THIS CASE, THERE WILL BE
QUEUING DELAY BEFORE THE LINK.
C) PROBABILITY THAT A GIVEN USER IS TRANSMITTING = 0.2
