Second term

And we are back!

Next Friday is our first lecture and the required reading are sections 4.1 and 4.2.1 of Kurose's. See you there.

Please note that semester marks have been published now (green column).

Update: By popular request first second term lecture has been moved to Wednesday February 8th. It will be held in classroom 1G 1.6 from 16:00 to 18:00.

Exercise 6

Some of you shown some concern about exercise number six of the exam. As a result I have reviewed the marking and a few of you have got your mark risen a bit. The main problem is twofold: whether you increase the congestion window by two or one after each acknowledge during slow start and what is the policy during congestion avoidance.

You can have a look at the proposed solution trace. And the policies on each case are as follows:

• Threshold: Same value on both sides of 3 MSS during all the exercise.
• Slow Start: each ACK increases CongWin value by one MSS.
• Congestion Avoidance: If during one RTT CongWin bytes are ACKed then CongWin is increased by one MSS (CongWin remains unchanged otherwise). 

However, those that may have chosen to increase by two MSS per ACK (given the fact delayed acknowledgments are used) during slow start also scored ok. Those that used a fractional increase of CongWin during Congestion Avoidance (ie. to increase MSS/CongWin per ACK) can also have a correct answer.

Interesting Java book

My friend Oscar Belmonte who is a professor at Jaume I university has published this interesting Java book you can download for free.

1st term marks and marked exams

You can have a look here at the test you did in the last class of the semester:

20120127104231838
The marked exams are going to be emailed to each one of you today, so you can see what you did right or wrong. A solved exam will be published soon too.

How come SSL type field is not encrypted?

All fields of SSL record header are not encrypted but its content is taken into account for MAC calculation. So if an attacker changes them, that record will be signal as invalid once MAC is verified by the receiver.

Kurose's chapter 8 slides

Are available in the file repository.

Last session for presenting your project

As we have one session pending for the rest of the projects to be presented publicly, we will held that session next Monday, 16th January 2012 in "Seminario 3", in the 3rd floor or 1G building. See you there.

Last lecture of the semester

For this last lecture the previous reading is Kurose2010, section 8.5
Next Thursday in the lab the first eight projects will be presented. The format of that session is as follows:

• Each presenter has ten minutes to explain his project, that includes what the project is about, the actual code and a demo.
• Attendants will rate each presenter from 1 to 5 (larger is better) in a list that will be handed over to the instructor at the end of the session.
• Presentations may use (if desired) a set of slides (not required).
• Students may address the audience in the language of their choice.