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Homework

There are four homework assignments, each homework assignment is worth 100 points. The homework assignments are part of your preparation for the exam, therefore you have to collect at least 300 points for the four assignments in order to be able to sit for the exam. Individual homework assignments can be graded with any integer number between 0 and 100.

The homework solutions should be submitted individually (not in groups). You are not allowed to copy your assignment from another student or from another source. See code of honour regulation 3. Violation of this rule will be considered as cheating.

There is a submission deadline for every homework assignment (see below). You will have to submit your solution on the web using the homework submission system. You will be asked the course username/password to access the front page. From the front page there is a link to the KTH authentication system, through which you can authenticate yourself using your KTH username/password. Help is available on the front page via a link before login, and in the status bar after login.

Please report problems to György Dán via e-mail.

After the submission deadline we publish the solutions of the assignment on the course home page (below), and you will be able to see the solution submitted by a fellow student in the homework submission system, which you will have to gradewithin 48 hours. You will have to submit your evaluation of your fellow student's homework through the homework submission system. You will only obtain points for your submitted assignment if you submit the evaluation for your fellow student.

In order to ensure that everyone can read the submitted documents we ask you to use PDF format and to write your solutions and review in English. To keep the server load managable, the file size is limited to 500KB.
Please name your documents "lastname_firstname_hwX.pdf", where X is the homework number. Please avoid using accented letters in the file name.
(Hint: OpenOffice exports to PDF, MS Office can export to PDF using the freeware doPDF PDF converter. There are also other freeware converters available on the web, e.g., Text2PDFfor text to PDF conversion.)

  • Homework 1 IP [Download]
    - submission deadline 17:00 CET on 2013.Sept.11.
    - review deadline 17:00 CET on 2013.Sept.13.
  • Homework 2 IP, ARP, Routing, ICMP [Download]
    - submission deadline 17:00 CET on 2013.Sept.18.
    - review deadline 17:00 CET on 2013.Sept.20.
  • Homework 3 TCP, Application layer and autoconfiguration [Download] 
    - submission deadline 17:00 CET on 2013.Oct. 4.
    - review deadline 17:00 CET on 2013.Oct. 8.
  • Homework 4 Autoconfiguration, network address translation, etc [Download]
    - submission deadline 17:00 CET on 2013.Oct. 11.
    - review deadline 17:00 CET on 2013.Oct. 15.
  • Homework 5 Make-up opportunity [Download]
    - submission deadline 17:00 CET on 2013.Oct. 22.
    - review deadline 17:00 CET on 2013.Oct. 24.

György Dán skapade sidan 11 juni 2013

kommenterade 13 september 2013

In Homework 2, first sentence "The figure above illustrates four hosts H1, H2, H3, H4 and H5...". Is the figure correct or should it be four hosts?

Anmäl missbruk
Administratör kommenterade 13 september 2013

The figure is correct. I upload a corrected version.

Anmäl missbruk
kommenterade 17 september 2013

Homework 2, 1.a. "Provide the state of the five ARP caches". As far as I understand there's six ARP caches H1-H5 and router R1. Should we answer with five or six caches?

Anmäl missbruk
Administratör kommenterade 17 september 2013

6 please.

Anmäl missbruk
Peter Sjödin redigerade 27 september 2013

There are four homework assignments, each homework assignment is worth 100 points. The homework assignments are part of your preparation for the exam, therefore you have to collect at least 300 points for the four assignments in order to be able to sit for the exam. Individual homework assignments can be graded with any integer number between 0 and 100.

The homework solutions should be submitted individually (not in groups). You are not allowed to copy your assignment from another student or from another source. See code of honour regulation 3. Violation of this rule will be considered as cheating.

There is a submission deadline for every homework assignment (see below). You will have to submit your solution on the web using the homework submission system. You will be asked the course username/password to access the front page. From the front page there is a link to the KTH authentication system, through which you can authenticate yourself using your KTH username/password. Help is available on the front page via a link before login, and in the status bar after login.

Please report problems to György Dán via e-mail.

After the submission deadline we publish the solutions of the assignment on the course home page (below), and you will be able to see the solution submitted by a fellow student in the homework submission system, which you will have to gradewithin 48 hours. You will have to submit your evaluation of your fellow student's homework through the homework submission system. You will only obtain points for your submitted assignment if you submit the evaluation for your fellow student.

In order to ensure that everyone can read the submitted documents we ask you to use PDF format and to write your solutions and review in English. To keep the server load managable, the file size is limited to 500KB. Please name your documents "lastname_firstname_hwX.pdf", where X is the homework number. Please avoid using accented letters in the file name. (Hint: OpenOffice exports to PDF, MS Office can export to PDF using the freeware doPDF PDF converter. There are also other freeware converters available on the web, e.g., Text2PDFfor text to PDF conversion.)


* Homework 1 IP [Download] [bkp:Download]- submission deadline 17:00 CET on 2013.Sept.11. - review deadline 17:00 CET on 2013.Sept.13. [Solutions]
* Homework 2 IP, ARP, Routing, ICMP [Download]- submission deadline 17:00 CET on 2013.Sept.18.- review deadline 17:00 CET on 2013.Sept.20. [Solutions]
* Homework 3 TCP, Application layer and DNS autoconfiguration [Download] - submission deadline 17:00 CET on 2013.Oct. 24.- review deadline 17:00 CET on 2013.Oct. 48.
* Homework 4 Autoconfiguration, network address translation, etc- submission deadline 17:00 CET on 2013.Oct. 9.- review deadline 17:00 CET on 2013.Oct. 11.

Lärare kommenterade 27 september 2013

Homework 3 is now available.

Anmäl missbruk
kommenterade 29 september 2013

In HW3 the "Web" part should consist of 25 p, but adding all the questions' points results in 30 p. This would make a total of 105 p on the Homework. I'm guessing 5 points should be removed somewhere?  

Anmäl missbruk
kommenterade 29 september 2013

In question 1, the propagation time (200ms) is it the end to end one way delay? or is it the total propagation delay? ie: do I need to multiply it by 2?

Anmäl missbruk
Lärare kommenterade 29 september 2013

200ms is the propagation time in one direction.

Anmäl missbruk
Lärare kommenterade 30 september 2013

There is now an updated version of HW3, with adjusted number of points on Q3 Web. Sorry for the mistake.

Anmäl missbruk
Lärare kommenterade 30 september 2013

We have received questions about the deadline for HW3. The deadline on the web is correct: Oct 4. 

We  allow one week for the homework, and then two additional (working) days for the review.

Anmäl missbruk
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kommenterade 3 oktober 2013

The homework references RFC 2988 which is obsoleted by RFC 6298. Would it not be more correct to use RFC 6298?

Anmäl missbruk
Lärare kommenterade 3 oktober 2013

You can use RFC6298, the only difference is the initial RTO value, which is allowed to be less than 3s as per RFC6298. Please write in the solution if you use RFC6298.

Anmäl missbruk
kommenterade 3 oktober 2013

Regarding Q3 in the TCP part. It says the delayed acknowledgement is 200ms (or at most two full segments). 

Do you mean that an acknowledgement is sent after receiving two segments since the last ACK or three segments since the last ACK?

Anmäl missbruk
Lärare kommenterade 3 oktober 2013

Yes, after 2 full sized segments, as required by TCP.

Anmäl missbruk
kommenterade 3 oktober 2013

Homework 3 question 3.e and 3.f. Can you clarify if you want us to calculate the time for one HTML page AND three images or only three images?

Anmäl missbruk
Lärare kommenterade 3 oktober 2013

The question is about the total time from clicking the link until the entire document is received. It is part of the problem to figure out what this means, and how the HTML document would be organized. So the question is, what happens when you click on the link? What would you receive as response? 

Anmäl missbruk
kommenterade 4 oktober 2013

In your lecture 8 TCP/UDP pdf, update of estimated RTT mean is given as

sRTT[k +1] = alpha *sRTT[k]+ (1 – alpha) *mRTT[k]

while RFC 2988 says

SRTT <- (1 - alpha) * SRTT + alpha * R'

Which one is correct?

Anmäl missbruk
Peter Sjödin redigerade 4 oktober 2013

There are four homework assignments, each homework assignment is worth 100 points. The homework assignments are part of your preparation for the exam, therefore you have to collect at least 300 points for the four assignments in order to be able to sit for the exam. Individual homework assignments can be graded with any integer number between 0 and 100.

The homework solutions should be submitted individually (not in groups). You are not allowed to copy your assignment from another student or from another source. See code of honour regulation 3. Violation of this rule will be considered as cheating.

There is a submission deadline for every homework assignment (see below). You will have to submit your solution on the web using the homework submission system. You will be asked the course username/password to access the front page. From the front page there is a link to the KTH authentication system, through which you can authenticate yourself using your KTH username/password. Help is available on the front page via a link before login, and in the status bar after login.

Please report problems to György Dán via e-mail.

After the submission deadline we publish the solutions of the assignment on the course home page (below), and you will be able to see the solution submitted by a fellow student in the homework submission system, which you will have to gradewithin 48 hours. You will have to submit your evaluation of your fellow student's homework through the homework submission system. You will only obtain points for your submitted assignment if you submit the evaluation for your fellow student.

In order to ensure that everyone can read the submitted documents we ask you to use PDF format and to write your solutions and review in English. To keep the server load managable, the file size is limited to 500KB. Please name your documents "lastname_firstname_hwX.pdf", where X is the homework number. Please avoid using accented letters in the file name. (Hint: OpenOffice exports to PDF, MS Office can export to PDF using the freeware doPDF PDF converter. There are also other freeware converters available on the web, e.g., Text2PDFfor text to PDF conversion.)


* Homework 1 IP [Download] [bkp:Download]- submission deadline 17:00 CET on 2013.Sept.11. - review deadline 17:00 CET on 2013.Sept.13. [Solutions]
* Homework 2 IP, ARP, Routing, ICMP [Download]- submission deadline 17:00 CET on 2013.Sept.18.- review deadline 17:00 CET on 2013.Sept.20. [Solutions]
* Homework 3 TCP, Application layer and autoconfiguration [Download] - submission deadline 17:00 CET on 2013.Oct. 4.- review deadline 17:00 CET on 2013.Oct. 8. [Solutions]
* Homework 4 Autoconfiguration, network address translation, etc [Download]- submission deadline 17:00 CET on 2013.Oct. 11.- review deadline 17:00 CET on 2013.Oct. 15.

Lärare kommenterade 4 oktober 2013

Always the RFC. In this case the two are equivalent, just use alpha'=(1-alpha)

Anmäl missbruk
kommenterade 5 oktober 2013

Hello, I am looking at the correction of the third homework, and in the TCP part, there is something I don't undersand. How come B recieves the first segment at t0+201ms if it is sent at t0 and transmission time is 200ms ?

Anmäl missbruk
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Lärare kommenterade 5 oktober 2013

The transmission time is 1ms. The one way delay is 200ms. This together gives 201ms.

Anmäl missbruk
Lärare kommenterade 5 oktober 2013

The sender increases the CWND by min(N,MSS) upon every ACK, where N is the number of bytes acknowledged.

Anmäl missbruk
Lärare kommenterade 5 oktober 2013

The original solution for the TCP question did not consider the effect of delayed ACKs as in RFC5681 equation (2). A revised solution for the TCP problem is available above. Sorry for the error in the original solution. 

Anmäl missbruk
kommenterade 5 oktober 2013

I don't understand why we should consider the transmission time for the first segment since it is actually writen in the assignement that the first segment is SENT at t0.

Anmäl missbruk
kommenterade 5 oktober 2013

In part 4 DHCP, you mentioned that Transaction ID should be the same value for DHCP DISCOVER and DHCP OFFER, and a new value to be used in DHCP REQUEST and DHCP ACK.

but according to microsoft (http://support.microsoft.com/kb/169289)and some other resources that this transcation ID remains same.

Please rectify.

Anmäl missbruk
kommenterade 5 oktober 2013

The Revised solution for Problem for HW3 seems to be missing a few pages. Makes me unable to grade my fellow student.

Anmäl missbruk
kommenterade 5 oktober 2013

Exactly, I also kept the transaction IDs the same cause I read about it from the same page

Anmäl missbruk
kommenterade 6 oktober 2013

Should i just give my guy full points for all questions except #1?

Anmäl missbruk
kommenterade 6 oktober 2013

In fact I had the confusion about DHCP as well, so I tested it on three different WIFI networks monitoring traffic with Wireshark - the transaction ID stayed the same across the full transaction in all cases  (that is from DHCPDISCOVER to DHCPACK) - dhcp client in this case was Linux dhclient and the access points used were Linksys, Apple and the KTH ones (though I guess in this case it would probably be more dependent on the client used).

Anmäl missbruk
kommenterade 6 oktober 2013

@Daniel: The only solution that has been revised so far is for problem 1. For the rest, use the original set of solutions. They seem to be (mostly) correct, except possibly the DHCP transaction ID being discussed.

Anmäl missbruk
Lärare kommenterade 6 oktober 2013

@Daniel: As Mikael says, the revised solution concerns only problem 1.

@Kevin: If you assume it is the last bit of the segment that leaves at t0, the solution would only differ in that all time stamps would be 1ms less. The measured round trip times, and the sequence of segments exchanged would be the same. I would say this is a minor issue, and a solution can be correct based on this assumption.

Anmäl missbruk
kommenterade 6 oktober 2013

oh I shouldve looked more carefully.

Anmäl missbruk
kommenterade 6 oktober 2013

Ok thank you.
Other question for the part 3 : why don't we consider the time necessary for closure of the connection ?

Anmäl missbruk
Lärare kommenterade 6 oktober 2013

Because upon receiving the last ACK you can be certain that the receiver received all data. You do not need to close the connection for that.

Anmäl missbruk
kommenterade 6 oktober 2013

Ok I see. Thank you

Anmäl missbruk
kommenterade 6 oktober 2013

It seems an error made by my partner and me is to increase CWND by the byte amount ACKed in each ACK (this is what is called byte-counting?) where as you have stated here it is min(N,MSS). Is this a difference between some different RFCs and/or the book and "reality"?

I haven't checked properly where we got the notion that CWND increases by the byte amount ACKed from, but clearly we both made this assumption.

Anmäl missbruk
kommenterade 6 oktober 2013

Also, György - no reply regarding the transaction IDs in DHCP ? In my wireshark logs it sure seems like dhclient uses the same id. Am I mistaken somehow?

Anmäl missbruk
kommenterade 6 oktober 2013

It seems that according to RFC 2131, the XID to use in DHCPREQUEST message "should be 'xid' from server selected by DHCPOFFER message", also further down in the RFC "The DHCPREQUEST message contains the same 'xid' as the DHCPOFFER message.".

My client doesnt include yiaddr with DHCPREQUEST either.. I guess this is a prime example of how RFC and implementation does not always jive, as RFC clearly states (as the solution also does that):

"o DHCPREQUEST generated during SELECTING state:"

"requested IP address' MUST be filled in with the yiaddr value from the chosen DHCPOFFER."

Anmäl missbruk
Markus Hidell redigerade 6 oktober 2013

There are four homework assignments, each homework assignment is worth 100 points. The homework assignments are part of your preparation for the exam, therefore you have to collect at least 300 points for the four assignments in order to be able to sit for the exam. Individual homework assignments can be graded with any integer number between 0 and 100.

The homework solutions should be submitted individually (not in groups). You are not allowed to copy your assignment from another student or from another source. See code of honour regulation 3. Violation of this rule will be considered as cheating.

There is a submission deadline for every homework assignment (see below). You will have to submit your solution on the web using the homework submission system. You will be asked the course username/password to access the front page. From the front page there is a link to the KTH authentication system, through which you can authenticate yourself using your KTH username/password. Help is available on the front page via a link before login, and in the status bar after login.

Please report problems to György Dán via e-mail.

After the submission deadline we publish the solutions of the assignment on the course home page (below), and you will be able to see the solution submitted by a fellow student in the homework submission system, which you will have to gradewithin 48 hours. You will have to submit your evaluation of your fellow student's homework through the homework submission system. You will only obtain points for your submitted assignment if you submit the evaluation for your fellow student.

In order to ensure that everyone can read the submitted documents we ask you to use PDF format and to write your solutions and review in English. To keep the server load managable, the file size is limited to 500KB. Please name your documents "lastname_firstname_hwX.pdf", where X is the homework number. Please avoid using accented letters in the file name. (Hint: OpenOffice exports to PDF, MS Office can export to PDF using the freeware doPDF PDF converter. There are also other freeware converters available on the web, e.g., Text2PDFfor text to PDF conversion.)


* Homework 1 IP [Download] [bkp:Download]- submission deadline 17:00 CET on 2013.Sept.11. - review deadline 17:00 CET on 2013.Sept.13. [Solutions]
* Homework 2 IP, ARP, Routing, ICMP [Download]- submission deadline 17:00 CET on 2013.Sept.18.- review deadline 17:00 CET on 2013.Sept.20. [Solutions]
* Homework 3 TCP, Application layer and autoconfiguration [Download] - submission deadline 17:00 CET on 2013.Oct. 4.- review deadline 17:00 CET on 2013.Oct. 8. [Solutions-updated for problem 4] [Revised solution for Problem 1]
* Homework 4 Autoconfiguration, network address translation, etc [Download]- submission deadline 17:00 CET on 2013.Oct. 11.- review deadline 17:00 CET on 2013.Oct. 15.

Lärare kommenterade 6 oktober 2013

Several DHCP implementations actually turn out to use the same transaction ID for all the four messages DISCOVER, OFFER, REQUEST, ACK. Solutions with the same transaction ID for these messages should be considered OK. The solutions have been updated.

/Markus

Anmäl missbruk
Lärare kommenterade 6 oktober 2013

@Linus: Yes, this is exactly the difference between the original solution to problem 1 and the revised solution. The CWND should be increased by max(N,MSS) for every received ACK. If delayed ACKs are used then slow start is slower than it would be without delayed ACKs because of this update rule.

Anmäl missbruk
Peter Sjödin redigerade 7 oktober 2013

There are four homework assignments, each homework assignment is worth 100 points. The homework assignments are part of your preparation for the exam, therefore you have to collect at least 300 points for the four assignments in order to be able to sit for the exam. Individual homework assignments can be graded with any integer number between 0 and 100.

The homework solutions should be submitted individually (not in groups). You are not allowed to copy your assignment from another student or from another source. See code of honour regulation 3. Violation of this rule will be considered as cheating.

There is a submission deadline for every homework assignment (see below). You will have to submit your solution on the web using the homework submission system. You will be asked the course username/password to access the front page. From the front page there is a link to the KTH authentication system, through which you can authenticate yourself using your KTH username/password. Help is available on the front page via a link before login, and in the status bar after login.

Please report problems to György Dán via e-mail.

After the submission deadline we publish the solutions of the assignment on the course home page (below), and you will be able to see the solution submitted by a fellow student in the homework submission system, which you will have to gradewithin 48 hours. You will have to submit your evaluation of your fellow student's homework through the homework submission system. You will only obtain points for your submitted assignment if you submit the evaluation for your fellow student.

In order to ensure that everyone can read the submitted documents we ask you to use PDF format and to write your solutions and review in English. To keep the server load managable, the file size is limited to 500KB. Please name your documents "lastname_firstname_hwX.pdf", where X is the homework number. Please avoid using accented letters in the file name. (Hint: OpenOffice exports to PDF, MS Office can export to PDF using the freeware doPDF PDF converter. There are also other freeware converters available on the web, e.g., Text2PDFfor text to PDF conversion.)


* Homework 1 IP [Download] [bkp:Download]- submission deadline 17:00 CET on 2013.Sept.11. - review deadline 17:00 CET on 2013.Sept.13. [Solutions]
* Homework 2 IP, ARP, Routing, ICMP [Download]- submission deadline 17:00 CET on 2013.Sept.18.- review deadline 17:00 CET on 2013.Sept.20. [Solutions]
* Homework 3 TCP, Application layer and autoconfiguration [Download] - submission deadline 17:00 CET on 2013.Oct. 4.- review deadline 17:00 CET on 2013.Oct. 8. [Solutions- – updated for problem 4] [Revised solution for Problem 11 & 4]
* Homework 4 Autoconfiguration, network address translation, etc [Download]- submission deadline 17:00 CET on 2013.Oct. 11.- review deadline 17:00 CET on 2013.Oct. 15.

kommenterade 7 oktober 2013

im unable to download Homework 4. moodle gives me an empty link.

Anmäl missbruk
kommenterade 7 oktober 2013

nevermind my browser decided it was a harmful file for some reason.

Anmäl missbruk
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kommenterade 9 oktober 2013

It seems like it is not possible to upload HW4 on the homework submission system (yet?)?

Anmäl missbruk
Lärare kommenterade 9 oktober 2013

It should be possible now.

Anmäl missbruk
Lärare kommenterade 9 oktober 2013

A reminder to Googledocs users: please double-triple-quadruple check the PDF that you generate from googledocs before you upload it to the system. There seems to be an issue that may lead to generating a PDF that contains a warning message but not your document...

Anmäl missbruk
kommenterade 11 oktober 2013

Hmm. The text in question 5 says we should consider host 10.0.0.3, but the arrows in the figure go from/to 10.0.0.1. Which one is it?

Anmäl missbruk
kommenterade 11 oktober 2013

Nevermind, I realized now this is because the figure is from the book.

Anmäl missbruk
Lärare kommenterade 11 oktober 2013

The intention was that you should consider host 10.0.0.3 so the arrows should go to/from 10.0.0.3. It has now been corrected, but correct solutions based communication to/from host 10.0.0.1 should also be considered OK.

Anmäl missbruk
Peter Sjödin redigerade 11 oktober 2013

There are four homework assignments, each homework assignment is worth 100 points. The homework assignments are part of your preparation for the exam, therefore you have to collect at least 300 points for the four assignments in order to be able to sit for the exam. Individual homework assignments can be graded with any integer number between 0 and 100.

The homework solutions should be submitted individually (not in groups). You are not allowed to copy your assignment from another student or from another source. See code of honour regulation 3. Violation of this rule will be considered as cheating.

There is a submission deadline for every homework assignment (see below). You will have to submit your solution on the web using the homework submission system. You will be asked the course username/password to access the front page. From the front page there is a link to the KTH authentication system, through which you can authenticate yourself using your KTH username/password. Help is available on the front page via a link before login, and in the status bar after login.

Please report problems to György Dán via e-mail.

After the submission deadline we publish the solutions of the assignment on the course home page (below), and you will be able to see the solution submitted by a fellow student in the homework submission system, which you will have to gradewithin 48 hours. You will have to submit your evaluation of your fellow student's homework through the homework submission system. You will only obtain points for your submitted assignment if you submit the evaluation for your fellow student.

In order to ensure that everyone can read the submitted documents we ask you to use PDF format and to write your solutions and review in English. To keep the server load managable, the file size is limited to 500KB. Please name your documents "lastname_firstname_hwX.pdf", where X is the homework number. Please avoid using accented letters in the file name. (Hint: OpenOffice exports to PDF, MS Office can export to PDF using the freeware doPDF PDF converter. There are also other freeware converters available on the web, e.g., Text2PDFfor text to PDF conversion.)


* Homework 1 IP [Download] [bkp:Download]- submission deadline 17:00 CET on 2013.Sept.11. - review deadline 17:00 CET on 2013.Sept.13. [Solutions]
* Homework 2 IP, ARP, Routing, ICMP [Download]- submission deadline 17:00 CET on 2013.Sept.18.- review deadline 17:00 CET on 2013.Sept.20. [Solutions]
* Homework 3 TCP, Application layer and autoconfiguration [Download] - submission deadline 17:00 CET on 2013.Oct. 4.- review deadline 17:00 CET on 2013.Oct. 8. [Solutions – updated for problem 1 & 4] Homework 3 updated solutions
* Homework 4 Autoconfiguration, network address translation, etc [Download]- submission deadline 17:00 CET on 2013.Oct. 11.- review deadline 17:00 CET on 2013.Oct. 15. [Solutions]

Peter Sjödin flyttade sidan från HT 2013, 50922 11 oktober 2013

kommenterade 11 oktober 2013

Hello! I have two questions about the solutions for homework 4.

1.b) Isn't the purpose for multiple name servers both redudancy and effeciency? Spreading the requests on multiple machines reduces the load on each machine which makes it possible to response faster.

2.a) There's an IPSec trailer for transport mode at page 859 in the book (TCP/IP Protocol Suite 4th ed). Why is it omitted in the solution?

Anmäl missbruk
kommenterade 12 oktober 2013

I assume that any port used in Q5 above port #1023 is valid?

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Lärare kommenterade 14 oktober 2013

Hi,

regarding the question about IPsec trailer, we have discussed two different encapsulations: ESP and AH. In the course book on page 859 they seem to assume that the figure illustrates ESP encapsulation, even though it is not explicitly stated (they only call it "IPsec"). In ESP, there is a trailer. Question 2a in HW4 is about AH encapsulation, and there is no trailer in AH encapsulation.

Regarding Q5 in HW4, any port number >1023 is OK.

/Markus

Anmäl missbruk
Lärare kommenterade 14 oktober 2013

@Frej Connolly: Regarding 1.b, you are right that adding more servers will increase capacity. I would not say it is the reason why organizations use multiple name servers, though. As a way of doing load balancing, this method has limitations. It is difficult to control how the load is distributed over the servers due to caching etc. The answer we are looking for here is related to availability, and that is the reason for having multiple servers that is mentioned in the textbook.

If a solution does not cover availability/reliability, there should be deduction in points. 

Anmäl missbruk
Peter Sjödin redigerade 15 oktober 2013

There are four homework assignments, each homework assignment is worth 100 points. The homework assignments are part of your preparation for the exam, therefore you have to collect at least 300 points for the four assignments in order to be able to sit for the exam. Individual homework assignments can be graded with any integer number between 0 and 100.

The homework solutions should be submitted individually (not in groups). You are not allowed to copy your assignment from another student or from another source. See code of honour regulation 3. Violation of this rule will be considered as cheating.

There is a submission deadline for every homework assignment (see below). You will have to submit your solution on the web using the homework submission system. You will be asked the course username/password to access the front page. From the front page there is a link to the KTH authentication system, through which you can authenticate yourself using your KTH username/password. Help is available on the front page via a link before login, and in the status bar after login.

Please report problems to György Dán via e-mail.

After the submission deadline we publish the solutions of the assignment on the course home page (below), and you will be able to see the solution submitted by a fellow student in the homework submission system, which you will have to gradewithin 48 hours. You will have to submit your evaluation of your fellow student's homework through the homework submission system. You will only obtain points for your submitted assignment if you submit the evaluation for your fellow student.

In order to ensure that everyone can read the submitted documents we ask you to use PDF format and to write your solutions and review in English. To keep the server load managable, the file size is limited to 500KB. Please name your documents "lastname_firstname_hwX.pdf", where X is the homework number. Please avoid using accented letters in the file name. (Hint: OpenOffice exports to PDF, MS Office can export to PDF using the freeware doPDF PDF converter. There are also other freeware converters available on the web, e.g., Text2PDFfor text to PDF conversion.)


* Homework 1 IP [Download] [bkp:Download]- submission deadline 17:00 CET on 2013.Sept.11. - review deadline 17:00 CET on 2013.Sept.13. [Solutions]
* Homework 2 IP, ARP, Routing, ICMP [Download]- submission deadline 17:00 CET on 2013.Sept.18.- review deadline 17:00 CET on 2013.Sept.20. [Solutions]
* Homework 3 TCP, Application layer and autoconfiguration [Download] - submission deadline 17:00 CET on 2013.Oct. 4.- review deadline 17:00 CET on 2013.Oct. 8. [Solutions – updated for problem 1 & 4] Homework 3 updated solutions
* Homework 4 Autoconfiguration, network address translation, etc [Download]- submission deadline 17:00 CET on 2013.Oct. 11.- review deadline 17:00 CET on 2013.Oct. 15. [Solutions]
* Homework 5 Make-up opportunity- submission deadline 17:00 CET on 2013.Oct. 22.- review deadline 17:00 CET on 2013.Oct. 24.

kommenterade 15 oktober 2013

What happens when the person who was to review my homework dosn't upload anything before the deadline?

Anmäl missbruk
kommenterade 15 oktober 2013

The same case is with me. I haven't got my grade points for hw4.

Anmäl missbruk
Lärare kommenterade 15 oktober 2013

Please wait a bit, the grading should become available soon.

Anmäl missbruk
kommenterade 15 oktober 2013

Have you uploaded the gradings? I haven't received a review on my homework yet.

Anmäl missbruk
En användare har tagit bort sin kommentar
En användare har tagit bort sin kommentar
Peter Sjödin redigerade 16 oktober 2013

There are four homework assignments, each homework assignment is worth 100 points. The homework assignments are part of your preparation for the exam, therefore you have to collect at least 300 points for the four assignments in order to be able to sit for the exam. Individual homework assignments can be graded with any integer number between 0 and 100.

The homework solutions should be submitted individually (not in groups). You are not allowed to copy your assignment from another student or from another source. See code of honour regulation 3. Violation of this rule will be considered as cheating.

There is a submission deadline for every homework assignment (see below). You will have to submit your solution on the web using the homework submission system. You will be asked the course username/password to access the front page. From the front page there is a link to the KTH authentication system, through which you can authenticate yourself using your KTH username/password. Help is available on the front page via a link before login, and in the status bar after login.

Please report problems to György Dán via e-mail.

After the submission deadline we publish the solutions of the assignment on the course home page (below), and you will be able to see the solution submitted by a fellow student in the homework submission system, which you will have to gradewithin 48 hours. You will have to submit your evaluation of your fellow student's homework through the homework submission system. You will only obtain points for your submitted assignment if you submit the evaluation for your fellow student.

In order to ensure that everyone can read the submitted documents we ask you to use PDF format and to write your solutions and review in English. To keep the server load managable, the file size is limited to 500KB. Please name your documents "lastname_firstname_hwX.pdf", where X is the homework number. Please avoid using accented letters in the file name. (Hint: OpenOffice exports to PDF, MS Office can export to PDF using the freeware doPDF PDF converter. There are also other freeware converters available on the web, e.g., Text2PDFfor text to PDF conversion.)


* Homework 1 IP [Download] [bkp:Download]- submission deadline 17:00 CET on 2013.Sept.11. - review deadline 17:00 CET on 2013.Sept.13. [Solutions]
* Homework 2 IP, ARP, Routing, ICMP [Download]- submission deadline 17:00 CET on 2013.Sept.18.- review deadline 17:00 CET on 2013.Sept.20. [Solutions]
* Homework 3 TCP, Application layer and autoconfiguration [Download] - submission deadline 17:00 CET on 2013.Oct. 4.- review deadline 17:00 CET on 2013.Oct. 8. [Solutions – updated for problem 1 & 4] Homework 3 updated solutions
* Homework 4 Autoconfiguration, network address translation, etc [Download]- submission deadline 17:00 CET on 2013.Oct. 11.- review deadline 17:00 CET on 2013.Oct. 15. [Solutions]
* Homework 5 Make-up opportunity [Download]- submission deadline 17:00 CET on 2013.Oct. 22.- review deadline 17:00 CET on 2013.Oct. 24.

Lärare kommenterade 16 oktober 2013

Homework 5 is now available.

Even though it is primarily for those who do not have sufficiently many points, we encourage all students to participate. It is a very good way to prepare for the exam. 

Anmäl missbruk
En användare har tagit bort sin kommentar

Peter Sjödin flyttade sidan från Internetworking (EP2120) 16 oktober 2013

Peter Sjödin flyttade sidan från HT 2012, 50694 16 oktober 2013

Lärare kommenterade 17 oktober 2013

Homework 5 has been updated. There were a few minors errors. The corrections are marked in yellow.

Anmäl missbruk
kommenterade 17 oktober 2013

@Teachers Here's a suggestion for next time. Utilize KTH social and create one wiki page per homework with the instructions (and solutions!) as text in the wiki page instead of in a pdf. It will be easier for us to see what changes you've made using the built-in version control system. That might also lead to another positive side effect that the discussions will be more structured if they're decoupled, instead of having all >70 comments about any homework on one page.

Anmäl missbruk
En person gillar kommentaren
kommenterade 21 oktober 2013

In HW5, multimedia communication part (b), is the queston correct?

shouldn't it be what does it provide, that TCP does not? 

Anmäl missbruk
Lärare kommenterade 22 oktober 2013

8. Multimedia Communication part b) in HW5 is correctly phrased. The question is, what functionality does RTP add? You could, in theory, have the video frames directly in UDP instead. So the comparison is between (plain) UDP and RTP over UDP. 

Anmäl missbruk
kommenterade 23 oktober 2013

Where is the solution to Homework 5?

Anmäl missbruk
Peter Sjödin redigerade 23 oktober 2013

There are four homework assignments, each homework assignment is worth 100 points. The homework assignments are part of your preparation for the exam, therefore you have to collect at least 300 points for the four assignments in order to be able to sit for the exam. Individual homework assignments can be graded with any integer number between 0 and 100.

The homework solutions should be submitted individually (not in groups). You are not allowed to copy your assignment from another student or from another source. See code of honour regulation 3. Violation of this rule will be considered as cheating.

There is a submission deadline for every homework assignment (see below). You will have to submit your solution on the web using the homework submission system. You will be asked the course username/password to access the front page. From the front page there is a link to the KTH authentication system, through which you can authenticate yourself using your KTH username/password. Help is available on the front page via a link before login, and in the status bar after login.

Please report problems to György Dán via e-mail.

After the submission deadline we publish the solutions of the assignment on the course home page (below), and you will be able to see the solution submitted by a fellow student in the homework submission system, which you will have to gradewithin 48 hours. You will have to submit your evaluation of your fellow student's homework through the homework submission system. You will only obtain points for your submitted assignment if you submit the evaluation for your fellow student.

In order to ensure that everyone can read the submitted documents we ask you to use PDF format and to write your solutions and review in English. To keep the server load managable, the file size is limited to 500KB. Please name your documents "lastname_firstname_hwX.pdf", where X is the homework number. Please avoid using accented letters in the file name. (Hint: OpenOffice exports to PDF, MS Office can export to PDF using the freeware doPDF PDF converter. There are also other freeware converters available on the web, e.g., Text2PDFfor text to PDF conversion.)


* Homework 1 IP [Download] [bkp:Download]- submission deadline 17:00 CET on 2013.Sept.11. - review deadline 17:00 CET on 2013.Sept.13. [Solutions]
* Homework 2 IP, ARP, Routing, ICMP [Download]- submission deadline 17:00 CET on 2013.Sept.18.- review deadline 17:00 CET on 2013.Sept.20. [Solutions]
* Homework 3 TCP, Application layer and autoconfiguration [Download] - submission deadline 17:00 CET on 2013.Oct. 4.- review deadline 17:00 CET on 2013.Oct. 8. [Solutions – updated for problem 1 & 4] Homework 3 updated solutions
* Homework 4 Autoconfiguration, network address translation, etc [Download]- submission deadline 17:00 CET on 2013.Oct. 11.- review deadline 17:00 CET on 2013.Oct. 15. [Solutions]
* Homework 5 Make-up opportunity [Download]- submission deadline 17:00 CET on 2013.Oct. 22.- review deadline 17:00 CET on 2013.Oct. 24. [Solutions]

Lärare kommenterade 23 oktober 2013

The solutions for HW5 are available now.

Anmäl missbruk