Docsity
Log inSign up
Docsity
Prepare for your exams
Prepare for your exams

Study with the several resources on Docsity

Earn points to download
Earn points to download

Earn points by helping other students or get them with a premium plan

Guidelines and tips
Guidelines and tips
Sell on Docsity
Sell on Docsity
Log inSign up

Prepare for your exams

Study with the several resources on Docsity

Find documents

Prepare for your exams with the study notes shared by other students like you on Docsity

Search Store documents

The best documents sold by students who completed their studies

Search through all study resources
Docsity AINEW

Summarize your documents, ask them questions, convert them into quizzes and concept maps

Explore questions

Clear up your doubts by reading the answers to questions asked by your fellow students

Earn points to download

Earn points by helping other students or get them with a premium plan

Share documents
download point icon20 Points

For each uploaded document

Answer questions
download point icon5 Points

For each given answer (max 1 per day)

All the ways to get free points
Get points immediately

Choose a premium plan with all the points you need

Study Opportunities

Choose your next study program

Get in touch with the best universities in the world. Search through thousands of universities and official partners

Community

Ask the community

Ask the community for help and clear up your study doubts

University Rankings

Discover the best universities in your country according to Docsity users

Free resources

Our save-the-student-ebooks!

Download our free guides on studying techniques, anxiety management strategies, and thesis advice from Docsity tutors

From our blog

Exams and Study
Go to the blog

Sample Final Exam for CSC458 - Computer Networks at University of Toronto, Exams of Network Technologies and TCP/IP

University of TorontoNetwork Technologies and TCP/IP

A sample final exam for the course CSC458 - Computer Networks at the University of Toronto. The exam is designed to test the students' knowledge of computer networks and covers topics such as TCP, coding, and Random Early Detection (RED). The exam is closed book and closed notes, but students are allowed to use a non-programmable calculator and a double-sided sheet of notes. The exam consists of multiple-choice questions and open-ended questions that require students to show their reasoning.

Typology: Exams

2021/2022

Uploaded on 05/11/2023

anuprabha
anuprabha 🇺🇸

4.4

(18)

237 documents

1 / 4

Toggle sidebar

This page cannot be seen from the preview

Don't miss anything!

bg1
! !
CSC!458/2209!–!Computer!Networks! ! Page!1!of!4!
!
UNIVERSITY*OF*TORONTO!
Faculty!of!Arts!and!Science!
!
Sample!Final!Exam!
!
CSC458!–!Computer!Networks!
Professor!Yashar!Ganjali!
!
Duration!@!3!hours!
!
Examination!Aids:!!
NonCProgrammable!Calculators,!1!DoubleCSided!Page!of!Notes!
!
!
(i)!This!exam!is! closed! book! and!closed! notes.! However,! you! may! refer! to!a!sheet!of!8.5”x11”!
paper!(doubleCsided)!of!your!own!design.!You!can!also!use!a!nonCprogrammable!calculator.!
!
(ii)!Write!your!answers!on!the!exam!booklet!only.!You!will!not!receive!any!points!for!any!answer!
you!write!on!the!questions!paper.!!
!
(iii)!Make!sure!to!write!your!name!and!student!ID!clearly!on!the!exam!booklet.!!
!
(iv)!Show!your!reasoning!clearly.!If!your!reasoning!is!correct,!but!your!final!answer!is!wrong,!you!
will!receive!most!of!the!credit.!If! you!just!show!the!answer!without!reasoning,!and!your! answer!
is!wrong,!you!may!receive!no!points!at!all.!
!
!
Part!I!@!Multiple!Choice!Questions![4!points]!
Instructions:!In!the!following!questions,!check!the!assertion!that!appears! to!be!correct.!There!is!
exactly! one! correct! assertion! per! question.!Checking!the! correct! assertion! will! earn! you! one!
point.!If!you!check!an!incorrect!assertion,!or!if!you!check!more!than!one!assertion!per!question,!
you!will!not! earn! any! points! for! that! question.!Don’t& forget&to& enter& your& answer&on&the& exam&
booklet&and&NOT&on&this&questions&paper.!
!
1.!TCP.!Which!one!of!the!following!is!a!true!statement!about!TCP?!
(a) TCP!is!a!routing!protocol!used!throughout!the!Internet.!
(b) TCP!establishes!a!connection!between!two!endChosts!using!a!2Cway!handshake!scheme.!
(c) TCP!learns!of!congestion!via!packet!loss!or!variations!in!delay.!
(d) If!the!SYN!packet!sent!by!a!TCP!source!is!lost,!the!connection!is!closed.!
!
pf3
pf4

Partial preview of the text

Download Sample Final Exam for CSC458 - Computer Networks at University of Toronto and more Exams Network Technologies and TCP/IP in PDF only on Docsity!

UNIVERSITYOFTORONTO!

Faculty!of!Arts!and!Science!

Sample!Final!Exam!

CSC458!–!Computer!Networks!

Professor!Yashar!Ganjali!

Duration!@!3!hours!

Examination!Aids:!!

NonCProgrammable!Calculators,!1!DoubleCSided!Page!of!Notes!

(i)! This! exam! is! closed! book! and! closed! notes.! However,! you! may! refer! to! a! sheet! of! 8.5”x11”! paper!(doubleCsided)!of!your!own!design.!You!can!also!use!a!nonCprogrammable!calculator.! ! (ii)!Write!your!answers!on!the!exam!booklet!only.!You!will!not!receive!any!points!for!any!answer! you!write!on!the!questions!paper.!! ! (iii)!Make!sure!to!write!your!name!and!student!ID!clearly!on!the!exam!booklet.!! ! (iv)!Show!your!reasoning!clearly.!If!your!reasoning!is!correct,!but!your!final!answer!is!wrong,!you! will!receive!most!of!the!credit.!If!you!just!show!the!answer!without!reasoning,!and!your!answer! is!wrong,!you!may!receive!no!points!at!all.! ! ! Part!I!@!Multiple!Choice!Questions![4!points]! Instructions :!In!the!following!questions,!check!the!assertion!that!appears!to!be!correct.!There!is! exactly! one! correct! assertion! per! question.! Checking! the! correct! assertion! will! earn! you! one! point.!If!you!check!an!incorrect!assertion,!or!if!you!check!more!than!one!assertion!per!question,! you!will!not!earn!any!points!for!that!question.! Don’t&forget&to&enter&your&answer&on&the&exam& booklet&and&NOT&on&this&questions&paper.! ! 1.!TCP.! Which!one!of!the!following!is!a!true!statement!about!TCP?! (a) TCP!is!a!routing!protocol!used!throughout!the!Internet.! (b) TCP!establishes!a!connection!between!two!endChosts!using!a!2Cway!handshake!scheme.! (c) TCP!learns!of!congestion!via!packet!loss!or!variations!in!delay.! (d) If!the!SYN!packet!sent!by!a!TCP!source!is!lost,!the!connection!is!closed.! !

2.!Coding.! Suppose!a!10Mb/s!adapter!uses!Manchester!encoding!to!send!an!infinite!stream!of! 1’s!into!a!link.!How!many!transitions!per!second!will!the!signal!emerging!from!this!adapter!have?!! (a) 5!million!transitions!per!second.! (b) 10!million!transitions!per!second.! (c) 20!million!transitions!per!second.! (d) None!of!the!above.! ! 3.!Random!Early!Detection!(RED).! Which!of!the!following!is!true?! (a) !RED! is! tolerant! of! bursts! because! when! the! average! queue! occupancy! is! close! to! the! maximum!threshold,!there!is!still!room!in!the!queue!to!accept!new!bursts!of!packets.! (b) The! probability! of! RED! dropping! a! packet! belonging! to! a! flow! is! proportional! to! the! number!of!the!flow’s!packets!queued!at!the!router.! (c) RED!drops!packets!with!probability!1!when!the!router’s!queue!length!is!greater!than!the! maximum!threshold!value.! (d) If!two!flows,!one!TCP!and!one!UDP,!share!a!“RED”!router,!the!RED!algorithm!will!ensure! that!both!flows!receive!an!identical!share!of!the!outgoing!link.!! ! 4.!TCP. !Which!of!the!following!statements!is!true!about!TCP?! (a) TCP!segments!can!only!be!lost!when!router!queues!overflow.! (b) There! is! no! performance! benefit! to! having! a! window! size! larger! than! the! receiver! window!size.! (c) The!received!sees!duplicate!ACKs!(with!the!same!sequence!number)!only!when!a!packet! is!lost.!! (d) A!receiver!reduces!the!advertised!window!size!in!response!to!congestion.! ! ! ! ! Part!II!@!Definitions![3!points]! Describe!each!of!the!following!terms/concepts!clearly!and!concisely!(in!at!most!4C5!sentences).! For! each! of! these! terms,! explain! the! context! they! are! defined! at! –! which! protocol(s)! they! are! related!to,!when/where!they!are!used,!etc.!–!and!give!examples!if!possible.!Remember!to!use! the!exam!booklet!and!not!this!paper!for!your!answers.! ! 1 .!Fast!Retransmission! ! 2 .!Nagle’s!Algorithms! ! 3 .!Maximum!Segment!Size!(MSS)!! ! 4 .!Stub!Autonomous!System!(AS)! ! 5 .!Interior!Gateway!Protocol!(IGP)!! ! 6 .!Distance!Vector! ! ! !

(a)!How!many!RTTs!does!it!take!until!slowCstart!opens!the!send!window!to!1!MB?! ! (b)!How!many!RTTs!does!it!take!to!send!the!file?! ! (c)! If! the! time! to! send! the! file! is! given! by! the! number! of! required! RTTs! multiplied! by! the! link! latency,!what!is!the!effective!throughput!of!the!transfer?! ! (d)!What!percentage!of!the!link!bandwidth!is!utilized?! ! ! 4 .! Power! [6! points].! In! class! and! the! textbook,! we! used! the! somewhat! arbitrary! measure! of! “power”!to!characterize!network!performance.!The!usual!definition!of!power,! P ,!is!given!by:! !

average& delay

load

P =!

(a)!Explain!why!this!definition!of!power!is!commonly!used,!and!in!what!sense!it!is!“arbitrary”.! ! (b)! A! commonly! used! approximation! to! the! relationship! between! normalized! load! (which! can! vary! between! 0! and! 1! only)! and! average! delay! is

d ;! where! λ! is! the! normalized! load!

offered!to!the!network!and! d !is!the!average!delay!of!packets!passing!through!the!network.!Find! and!sketch!the!value!of!power,! P ,!as!a!function!of!the!offered!load!for!this!network.!Be!sure!to! show!the!minimum!and!maximum!values!of!power!and!load,!as!well!as!the!value!of!offered!load! that!maximizes!the!power.! ! (c)!Now!suppose!we!modify!the!definition!of!power!to!give!more!emphasis!to!throughput!than! delay,! i.e.! let! us! have

d

P

λ^2

= .! Sketch! the! new! power! function! against! the! offered! load,! being!

careful!to!show!the!maximum!and!minimum!values!of!both!load!and!power,!as!well!as!the!value! of!load!that!leads!to!maximum!power.!Comment!on!why!the!value!of!load!that!maximizes!the! power!is!larger!than!in!the!previous!part!of!the!question.! ! ! ! Total!Marks!=!2 5 !points! !