From CS 455 Spring 2011

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Mon, May 2 @ 11:32am - Final Exam

The final exam begins at 8:30am tomorrow (Tuesday) in our regular classroom in Spong. Like the mid-term, no calculators, notes, or books are allowed.

Mon, May 2 @ 11:30am - Prog 4 and Paper comments

I've added comments in Blackboard regarding your Program 4 and Final Paper grades.

Test 5 on Program 4:

 java AbrtReceiver 10005 700 0.4 5678
 java AbrtSender hostname 10005 5

It produced two long (> 1000 ms) delays in a row, no loss, resulting in premature timeouts and some duplicate ACKs being received.

The final papers were graded based on a total of 40 points, with 10 points each in the following categories:

Wed, Apr 20 @ 2:37pm - Prog 4 and Duplicate ACKs

In RDT 3.0, the sender sets a timer when it sends the data packet. If a duplicate ACK is received, the sender keeps waiting. Because of how I've suggested that you implement the timeout (with setSoTimeout), the timer will reset whenever you receive anything (even a duplicate ACK). To make things easier on you, you may allow the timer to reset when you receive a duplicate ACK.

Tue, Apr 19 @ 12:50pm - Prog 3 Grades and Final Exam Study Guide

Program 3 grades are now posted on Blackboard. I've also just posted the Final Exam Study Guide. We'll do a review in class next Tuesday (Apr 26).

Mon, Apr 11 @ 2:56pm - CS 555 Presentations Start Thursday

Please be in attendance (and on time) for these. There will be (easy) questions related to the presentations on the final exam. If you attend and are awake, you should be able to answer them. The presentation slides will not be posted online, so you must attend class.

Mon, Apr 4 @ 2:25pm - No classes

The class is not allowed for any of our assignments. For web communication, open a TCP socket and read/write some strings to the socket.

Tue, Mar 29 @ 5:10pm - Link-State Example

I've posted a new slide for the link-state example. It's under Mar 29 on the schedule and named 'link-state example'.

Tue, Mar 29 @ 8:40am - CS 555 Presentations

We will be scheduling CS 555 presentations (Apr 14-21) in class on Thursday. If you're not in class, you'll be assigned whatever slot is leftover.

Mon, Mar 28 @ 2:55pm - Prog 3 Clarification

The HTTP request capture program should remain running until the user closes it with Ctrl-C. The program should close the client socket after each request has been received, but leave the welcoming/listening socket open.

Thu, Mar 24 @ 4:00pm - Prog 2 Grades Posted

See Blackboard for grades and comments.

Sat, Feb 26 @ 2:00pm - Mid-Term Grades Posted

I've posted mid-term exam and updated current averages on Blackboard. The overall average for the mid-term exam was 87 -- good work! I'll hand back exams, and we'll discuss the solutions in class on Tuesday.

Tue, Feb 8 @ 9:54pm - Program 2 Assigned

Prog2 is now available. It is due March 15 (first Tuesday after Spring Break).

Mon, Jan 24 @ 10:38am - Program 1 Grades Posted

Grades are posted on Blackboard. See the file FULL-REPORT.txt attached under "User Feedback" for details on your grade. Test Cases

Wed, Jan 19 @ 9:15am - No Office Hours Today

Office hours are cancelled today (and probably tomorrow) due an illness in my family. I am available via email and IM (

Mon, Jan 17 @ 7am - No Office Hours Today

Due to the MLK holiday, I will not hold office hours today.

Thu, Jan 13 @ 12:55pm - No Java URL class

The use of the Java URL class is prohibited in this class. You have to do all String processing (and later, socket and application protocol programming) yourself.

Mon, Jan 3 @ 11:22am - Website and Email List

Please browse the class website, especially the Links page and Syllabus, before our first meeting next Tuesday. Also, please sign up for the class email list. Sign up with an email address that you check every day (Note: it does not have to be an address.)

Wed, Nov 10 @ 9:01am - What is This Course About?

I'll be updating these pages as we get closer to the semester, but check out the Fall 2009 offering for more information about what to expect.

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Page last modified on May 02, 2011, at 11:33 AM