COMP 431 Internet Services & Protocols Please sit in the front - PDF document

COMP 431 Internet Services & Protocols ◆ Please sit in the front of the classroom (first couple of rows) ◆ There are 3 “handouts” for today: » Course outline/syllabus » Lecture 0 slides » HW 1 description ◆ Please download a copy (now!) of each from the course web page at: http://www.cs.unc.edu/~jasleen/Courses/COMP431/ COMP 431: Overview 1 COMP 431 Internet Services & Protocols Internet Services & Protocols Jasleen Kaur jasleen@cs.unc.edu January 9, 2020 http://www.cs.unc.edu/~jasleen/Courses/COMP431 COMP 431: Overview 2

Why Study The Internet? It is a HUGE deal! ◆ Arguably one of the most important developments of the last 3 decades » Information Sharing » Means of Communication » Transactions » Services » Entertainment » Creation Empty and Meaningless Facebook Timeline Photo This course – how do (the foundations of) the Internet work? COMP 431: Overview 3 Example: Web Browsing Internet request data http://www.cnn.com response data COMP 431: Overview 4

Internet Services & Protocols Example Issues Internet ◆ How does the web work? » How does a client find a random web server? ❖ Is www.google.com really a “server”? » How does a request make its way from a web browser to a web server and how does the reply make it back? » How is it that all data transmitted arrives intact and in order? » How insecure is the connection and how secure is a secure connection? ◆ Why do we get the level of performance that we do? » Can one control (or even improve) the performance of their network connections? » How do the millions of web requests and responses that transit the UNC campus network every hour, share the capacity of the network? COMP 431: Overview 5 So, what is this course about? The Internet food chain of technology ◆ Application-level protocols » HTTP, FTP, SMTP (e-mail), DASH (streaming media), and the Domain Name System (DNS) » Socket programming and client/server computing ◆ Transport protocols » TCP and UDP » Congestion control principles and algorithms ◆ The Internet Protocol IP and Internet routing architecture and algorithms ◆ Physical-layer transmission technologies » Ethernet, Wireless LANs, modems COMP 431: Overview 6

COMP 431 Administrivia Prerequisites ◆ I assume that you have had: » COMP 411 — Computer Organization » COMP 410 — Data Structures ◆ I assume you’re comfortable programming in a language » We will be using Python in this course for socket programming (and I’m assuming you have enough programming experience to pick it up yourself) » This course (or the TAs) will not teach you Python ◆ Program operation will be described using Linux terminology » You should be comfortable with the Linux file system, file I/O, I/O redirection, basic Linux program development » Linux mini-tutorial is available on course web page (change machine names) 1. Try out all examples in tutorial 2. Complete HW 1 COMP 431: Overview 7 COMP 431 Administrivia Textbook & Handy References ◆ Computer Networking: A Top-Down Approach Featuring the Internet, 7 th Edition (2016) » By James F. Kurose and Keith W. Ross ◆ Learning Python, 5 th edition » By Mark Lutz, O’Reilly Media, 2013 COMP 431: Overview 8

COMP 431 Administrivia Other resources ◆ Course web page http://www.cs.unc.edu/~jasleen/Courses/COMP431 » Your source for copies of handouts, assignments, slides, online lectures , … » If you miss class (bad idea!) you can see if anything new was posted by checking the web site ◆ Lecture notes MUST be taken! Fill this space! Fill this space! COMP 431: Overview 9 COMP 431 Administrivia Online Forum ◆ Piazza.com – class discussion forum » Post your questions here (rather than email TAs or instructor) ❖ Use the appropriate “folder”: lecture, hw1, logistics, exam, … » Discuss possible “approaches” to homework problems or programming tasks ❖ But not full details (honor code violation) » Post answers to questions posted by others ❖ Folks who post answers will get credit for class participation ◆ Even if answers are incorrect ◆ As long as answer is not miniscule and is reasonably substantial » Anonymous posting allowed (I can see though) ◆ Piazza also used for class announcements (instead of email) => check it regularly !! (can be set up to send emails once/day) ◆ I expect you to use piazza heavily as a resource! » Add it NOW (linked from the course web page)! COMP 431: Overview 10

COMP 431 Administrivia Other online resources ◆ Sakai – all grades will be posted here ◆ Gradescope – written homeworks will need to be submitted here COMP 431: Overview 11 COMP 431 Administrivia Grading (all percentages approximate within 10%) ◆ Programming and written assignments (~50%) » Different assignments will have different weightage ◆ Midterm examination – tentatively, March 5 (~20%) ◆ Final examination (~30%) » Monday, April 27 at 12:00 PM ◆ Class participation used to raise grades by 0.3 grade points (e.g. add + to a letter grade; B+ ---> A-) » Both in-class and piazza participation (answering questions) counts » Piazza might count more in a large class ◆ Sorry, but auditing of this course is not allowed ◆ All grades will be posted on sakai.unc.edu COMP 431: Overview 12

COMP 431 Administrivia Programming and written assignments ◆ 4-6 programming/lab assignments ◆ 4-6 written homeworks ◆ Written homeworks will be collected on gradescope and are due by 10:50 am on the specified due date » Anything submitted after 10:49:59.99 EDT/EST is considered late ◆ Programming assignments are due by 10:50 am on the specified due date » Programs time-stamped after 10:49:59.99 EDT/EST on the due date are late (see HW 1 handout)! COMP 431: Overview 13 COMP 431 Administrivia 10% bonus grade if Late homework policy NO late days used ! ◆ Late submissions of written homeworks will NOT be accepted. » A grade of “0” if not submitted on time. ◆ Late submission of programming homework is “ OK ” but... » Only if it ’ s not too late » You have 4 “ late days ” that may be distributed as you please among all of the programming assignments ❖ Once the 4 th late day is used up there will be no extensions! ◆ Warning : The 3 rd assignment builds on the 1 st one! » If you ’ re late on the 1 st assignment you ’ ll have to work faster on the 3 rd one » If you don ’ t get a perfect score on the 1 st you ’ ll have to fix the problems before starting the 3 rd assignment COMP 431: Overview 14

COMP 431 Administrivia Missing class policy ◆ No make-up will be given for missing homeworks, exams, lectures » Make sure you attend all classes! ◆ Unless you have an “excused” absence, which includes: » Medical emergency, or a family loss/emergency (with documentation) ◆ For “excused” absences, » Written homeworks will be pro-rated » Programming assignments will need to be completed (and may include some pro-rated grade) » Mid-term may be pro-rated (from final), ❖ Or you may be given a “make-up” exam COMP 431: Overview 15 COMP 431 Administrivia Honor Code: Policy on collaboration ◆ Working in groups on assignments is OK but… » You can only collaborate with other students in this course » You can only collaborate on understanding the assignment and possible “approaches” ❖ Every student must craft their own final solution ❖ Every student must fully write up their own solution » All collaborators must be acknowledged in writing ◆ Programming assignments must be completed by each student individually » Code may never be shared » Collaboration on the mechanics of Linux/Python programming is OK ❖ Debugging or designing each other’s programs is not OK COMP 431: Overview 17

For Details on Course Policies ◆ Read the Handouts shared today » Course Syllabus » Slides » Homework 1 READ THESE HANDOUTS CAREFULLY. YOU ARE RESPONSIBLE FOR KNOWING THE GROUND-RULES FOR THIS COURSE! COMP 431: Overview 18 COMP 431 Administrivia Where to go for help? ◆ Ask questions in class! ◆ Post questions on piazza: » Do not send clarification questions by email – post them on piazza. » Do expect that other students will be answering these (and instructor and TAs will “endorse” good answers). » Don ’ t depend on an immediate answer ◆ Attend office hours » TAs and my office hours have been posted on the course web page ❖ At least two hours of TA office hour each working week day COMP 431: Overview 19

COMP 431 Administrivia How to get an “ A ” in COMP 431 ◆ Attend class regularly » Ask questions! » Exercise your understanding of course material on a daily basis ◆ Read the book (and read the discussions on piazza) ◆ Take (and study your) notes! » Beware the “ But I understand this ” syndrome ◆ Study the homework and in-class “ thought ” problems » Don ’ t just “ do ” the homework ◆ Try out end-of-chapter problems in textbook COMP 431: Overview 20 COMP 431 Administrivia How to get (no higher than) a “ D ” in COMP 431 ◆ Assume getting copies of handouts is sufficient » You still have to read the book! ◆ Don ’ t take notes in class » Handouts are purposefully incomplete! ◆ Miss class » What is said in class is important! ◆ Don’t take lectures posted online seriously ◆ Procrastinate and start assignments 2-3 days before deadline » Assignments are designed to require an average of at least10 hours of work outside of class each week COMP 431: Overview 21