A Win Win Approach Maximizing Wi-Fi Performance Using Game Theory https www.shibaura-it.ac.jp en headline detail 20240416 7070 001.html "When a new user connects to a Wi-Fi network, their position, speed, and interference can negatively affect the...

https arstechnica.com security 2024 04 zombie-worm-continues-to-infect-millions-of-ips-years-after-it-was-left-for-dead "A now-abandoned USB worm that backdoors connected devices has continued to self-replicate for years since its creators lost con...

ANONYMOUS wrote The longest in the Transperth dataset appears to be 'St Georges Tce Before William St Eastbound', so if we set the max to be 60 chars we'll be safe. (not a fan of dynamic memory?)

ANONYMOUS wrote You must be looking in the Transperth data, already. Yes, we'll just ignore any trips starting or finishing after midnight.

(hopefully not behind a paywall) Test Your Knowledge of Internet Acronyms https www.wired.com story gadget-lab-podcast-641

The next long-term-release of Ubuntu Linux, 24.04 (Noble Numbat) has just been released https canonical.com blog canonical-releases-ubuntu-24-04-noble-numbat However, I strongly suggest that you DON'T upgrade your system until at least the end of...

Hello Ethan, Let's assume (guarantee) that every journey can be completed on the day it was started - if a requested journey can't be completed by 11 59PM any day, then it "doesn't exist", and that condition should be reported back via the web-browse...

ANONYMOUS wrote The project requires two or more programs to communicate across a network. If all goes well - great - and the successes will be the correct meaningful results. But a number of things can go wrong - network messages not delivered, inva...

Fantastic article https arstechnica.com space 2024 04 recoding-voyager-1-nasas-interstellar-explorer-is-finally-making-sense-again Latency "Voyager 1 is flying on an outbound trajectory more than 15 billion miles (24 billion kilometers) from Ea...

Hello, ANONYMOUS wrote Not sure what you mean by 'hints' here. For the project, you may assume that all addresses in use are IPv4, as not all (limited) devices support IPv6 and not all systems choose to enable support it by default. They should all be ...

ANONYMOUS wrote Each station-server will be reading its station's timetable information from a file on the local disk. The file's name will not change. At any time, that file's contents may be updated to provide new timetable information, that should ...

ANONYMOUS wrote This is a very relevant question, and a good one to be asked at this stage, but it's the sort of question you should be discussing with your team members (please).

ANONYMOUS wrote The fastest journey is one that arrives at the destination soonest - even if you have to wait around at the starting platform before the first leg.

ANONYMOUS wrote Yes, that's exactly as expected. That is what the web-browser is sending the the 'nc' process, which is listening on port 4444. Probably because you're missing the colon before the 4444.

ANONYMOUS wrote Great - what was missing, or what did you have to correct?

ANONYMOUS wrote That's very odd - which platform? Wondering if you don't have a name mapping to 127.0.0.1 (which would be odd). Can you access - 127.0.0.1 4444 ?? Ahh, that's where I got up to yesterday before going home; I've marked it as 'Under Co...

ANONYMOUS wrote Yes, a station will almost certainly need to know (and remember) the names of its neighbour(s), which it can 'learn' simply by ask each neighbour.

A big thank you to the (embarrassingly large) number of students who have sent through their good wishes and very kind words. I'm not worried about anything, so I hope that no-one else is either. It's been a rough past 6 years, but have found that ...

ANONYMOUS wrote Going OK, so far, thanks. Maximum of 4 per team (stated on our unit's front webpage).

ANONYMOUS wrote For this to occur, each of the 3 slots must host exactly one transmission. If the 1st slot hosts a successful re-transmission by one node, the other two nodes must have chosen to not immediately retransmit, but to back-off for one slot...

ANONYMOUS wrote Yes; was discussed in this afternoon's tutorial.

ANONYMOUS wrote Yes (of course). An example test paper page attached.

ANONYMOUS wrote In practice the situation is blurred because the PL and DLL are combined in a Media Access Control (MAC) Layer, such as a single Ethernet interface card. If taken too literally - that the PL is just the wire itself, the scene where e...

ANONYMOUS wrote Discarding DATA will result in it, eventually, being re-transmitted, but not for the longest (anticipated) time. During the period of time, we hope that the congestion will 'die' down while the sender waits for the ACK (which will now...

ANONYMOUS wrote Yes, primarily because a node's transmissions can interfere with the transmissions of other nodes that it can't hear. p18 of Lect 5.

ANONYMOUS wrote There'll be 10-12 questions, each worth 1, 2, or 3 marks. No question requires a lengthy answer, instead marks are awarded based on the difficulty of the question and the sophistication of your answer. As some examples, from the list of...

ANONYMOUS wrote I'm not sure what point you're wishing to make here. In the leaky-bucket algorithm, one frame is transmitted for each 'drip' from the bucket (i.e. one frame is transmitted each time interval). This would occur regardless of whether th...

ANONYMOUS wrote Hello, yes, you are correct. I have corrected the last sentence on each of page 20 and page 21. (There seems to have been some poor cut-and-paste going on there - I wonder for how many years it went un-noticed...?) Thanks.

ANONYMOUS wrote This is the strongest answer of all the points made, above. Consider who the sequence numbers are for - in a DataLink Layer protocol, they're for 2 directly connected node - in a Network Layer protocol, they're for 2 nodes possibly ma...

ANONYMOUS wrote Actually Q5. Both of your points are correct, though 1 2 16 is not really a very low probability (consider 10s of thousands of frames per second), and there is a better answer than the 2 points you've provided. YES (taken care of by o...

ANONYMOUS wrote Hi, I'm not sure how to answer your question as I'm not sure what you mean by "I'm unable to use things..." The approach to piggybacking requires two timers, one supporting the retransmission of unacknowledged (outgoing) data, and one...

ANONYMOUS wrote Yes, a good answer. This second part wasn't asked in the question, but also correct. Good luck,

It means that the transmissions of all 3 nodes collided in slot-0 (the pre-condition for all three parts of this question), and you're asked what is the probability that all 3 nodes will successfully transmit their frame by the end of slot-3. As requi...

Sorry about that; things had moved. The correct URL is https teaching.csse.uwa.edu.au units CITS3002 resources flooding.zip

ANONYMOUS wrote Some sample questions, all taken from past papers, were linked to the test instructions today. No 'intense' calculations, but some questions may just require basic arithmetic.

ANONYMOUS wrote You don't ignore the new frames from that node, your DLL simply des not accept them from the layer above until the older frame has been successfully transmitted. (although we're not coding this question in any language), but in cnet ...

You are correct; it's the sort of thing I often do in my coding 'just in case', so it's not forgotten. It's termed defensive programming. Other examples include adding ... around code blocks, even if they're only a single line, and the pai...

That's great news - though we should all be frustrated, and curious, when things 'start' to work without our knowing why. We generally need to know 'why', so that we can re-apply the knowledge the next time we have a similar problem. But, of well. G...

ANONYMOUS wrote We've been discussing Aloha in the context of the data-link layer, with the DLL needing to successfully transmit one frame before beginning the process for the next one. We should complete the re-transmission, before starting a new...

Yes, such approaches work as well - you're using the fact that a timer is still 'running' as a Boolean value, which is the same as checking the equivalence of two integer values. However, as those integer values have a value that reflects how fut...

Yes, all of that is correct. The calculations are the same for both odd and even partity (the choice just determines what the 'final' value of each checkbit will be, and both the sender and receiver must agree on which (odd even) is being used.

ANONYMOUS wrote Glad that you solved it, though a shame that you had to re-install so many things to address what was probably a smaller problem too difficult to track down But you've chosen to stay with Windows-10, and not upgrade to 11? I find it ...

ANONYMOUS wrote A few other students have reported the same problem https secure.csse.uwa.edu.au run help3002?p np opt U54 hl segmentation but it's proving very difficult to pin-down. There's been no reported problems on a native-Linux installatio...

ANONYMOUS wrote Hi. It would be an impressive result if you were describing what we hope an improved protocol will do - deliver (and have accepted by the receiver) more messages per unit time (here, one hour), than the standard stop-and-wait. Whi...

I'm surprised that you're still seeing this problem. Have you downloaded and run the new installation script (from 16th March)? Does your system have newly installed usr local lib libc .1.0.dylib and usr local lib libunwind.1.dylib ?

Sort-of. It doesn't cause the errors, or bad design decisions, to surface, but if they're likely to surface 'sooner-or-later' it makes 'sooner-or-later' arrive sooner.

ANONYMOUS wrote The implementations of the standard CRC algorithms are certainly not examinable, and Labsheet-1 reinforced this by only treating the CRCs as 'black-boxes', which we called as functions, and they returned a result. You should know what ...

Please don't refer to old materials, particularly by a number which may change for this year.

ANONYMOUS wrote Either way can work - the best way, initially, is the way that simplest for your to implement and get working. If your frame-types are mutually exclusive, you can give them all distinct values, and just store one of them in a header ...

No, no need to store multiple checksums anywhere. We can always recalculate a checksum at any time required. We detect duplicates through the use of sequence-numbers. One advantage to using simulation is that you can 'exhaustively' check your protoc...

Hi Henry, Yes, you're correct - in practice, we should be calculating and verifying checksums for everything that could be corrupted (by the Physical Layer), so it applies for both data frames and acknowledgment frames. Those early slides trying to int...

ANONYMOUS wrote Yes - both 'ends' need to support the sending of their own data, receiving data from the other end, receiving acknowledgements (of your data) from the other end, and sending acknowledgements (about the data from the other end). We te...

For anyone still stuck using Apple Silicon, there's an updated installation script - https teaching.csse.uwa.edu.au units CITS3002 cnet downloads install-cnet.sh that, if necessary, downloads and installs the libraries discussed in this thread. Than...

ANONYMOUS wrote Do you have curl installed? If you run type curl does it report the pathname of the curl program?

ANONYMOUS wrote Well that's some good news for a change - thank you

It stands for 'bit error rate' - the probability that one-or-more bits in a frame will be corrupted. Yes, there's an additional problem that needs to be solved. It's easy to detect a damaged frame, and send back a negative-acknowledgement, but what n...

Wondering if anyone has experienced any problems installing or running cnet on Intel-based macOS? "No problems at all" is a valid response -) If you encountered a problem, and fixed it, what was the problem and its solution? Thank you,

Can you please give a bit of context - WSL2 we know, Windows-11? Ubuntu Linux? you've run the extended installation instructions (in the yellow box)? Try to work out why it works on other student's machines, but not yours.

The solution to this is not to do everything as root (the administrator), and not to install cnet as root, as you may be locked out from using it. But some of the suggestions, above, are correct - thank you. From the shell terminal, either on macO...

ANONYMOUS wrote I'm try to understand and fix this problem; I'm confused why a (non-existent) library that my code is not dependent upon, is a show-stopper. Really hope to have a solution today.

Hopefully this doesn't send you down a rabbit-hole, but try this https teaching.csse.uwa.edu.au units CITS3002 cnet downloads libunwind.1.dylib (I wish I knew why these libraries claim to be required - my code makes no reference to this (that's OK)...

Thank you - seems a very good solution (I wonder why Windows, or WSL-2, doesn't actually provide an Xserver as part of their distribution?). I have added this information to our installation instructions - https teaching.csse.uwa.edu.au units CITS30...

There really shouldn't be a need to (manually) do any of this. The real problem to be solved is why that cp command can't find a file you've just downloaded into the current directory.

ANONYMOUS wrote Great if this works. How does WT support manage setting up the windowing, by setting DISPLAY to a known, required value, or by directing a command's graphical output the a display server before the command is even invoked? Anyone else t...

What happened when you tried it?

ANONYMOUS wrote Still trying to resolve this one. I can't understand why your linker is looking in System Volumes Preboot Cryptexes ... for anything, unless you knowingly have an environment variable set, such as LD LIBRARY PATH Does u...

ANONYMOUS wrote I'm unable to repeat this on my Linux or macOS systems. Your system is?

ANONYMOUS wrote I remember this as a problem that some students had last year but, again, not all students are having it this year. Clearly your DISPLAY variable is set, to 0.0 , but that's not the correct value. Reading stackoverflow, again......

ANONYMOUS wrote Thanks very much for that I have updated the installation instructions here - https teaching.csse.uwa.edu.au units CITS3002 cnet install.php If others 'uncover' additional packages that are required, please send the details to me. G...

ANONYMOUS wrote You should be able to see your version with cat etc os-release Here's my thinking while your system has shared libraries for libm, libc, and libstdc (reported by ldd ) the error message suggests that your system has an...

ANONYMOUS wrote As we try to sort this out, please don't mix up topics - your comment, above, doesn't match this thread's Subject line. Not sure what you mean by 'compile-time issue'. Do you mean on my end, when building the pre-built binaries?

I think that your macOS systems have Xcode installed (as required), but not the Command Line Tools. You can install them with xcode-select --install and then xcode-select -p should report their location.

When you run otool -L usr local bin cnet (it's very wide) do you see any mention of rp t , s o a i , o i c

What Linux distribution are you running inside WSL-2 ? It's rather unusual for a Linux distribution not to come with glibc. Can you provide the full (long) output from ldd usr local bin cnet on your system? It should show what's installed, and w...

I don't really know what that file is for, but the web suggests to install a package with shell sudo apt install libxkbcommon0 ( https packages.ubuntu.com mantic i386 libxkbcommon0 filelist ) ??

Did it also download stuff and install correctly (seemingly)? Which platform?

Actually, you just caught me updating something (and the Cloudflare cache takes minutes to update new stuff). Working now for me....

... from https teaching.csse.uwa.edu.au units CITS3002 labsheets labsheet2.php For Labsheets 2-4 we'll be using (my) network simulation software named cnet https teaching.csse.uwa.edu.au units CITS3002 cnet cnet is not installed on laboratory com...

... from our Schedule page https teaching.csse.uwa.edu.au units CITS3002 schedule.php Sample solutions and discussion will be available every week, and you can raise your thoughts in the Tutorials, too, but I won't make an announcement about them ev...

ANONYMOUS wrote Keep in mind that Hamming's mechanism (algorithm) requires the original input data to be 7 bits long, to calculate 4 checkbits, and to 'merge' the data and checkbits together to form a total of 11 output bits. From our Resources page ...

Hi Sebastian, For this exercise, we're not really passing frames across a network, and not having the network (possibly) corrupt those frames, we're just simulating emulating all of the actions with a single process on a single computer (no network re...

The discussion questions for our 1st tutorial, next week, are available from our Schedule page https teaching.csse.uwa.edu.au units CITS3002 schedule.php Please also note that the 2nd tutorial slot, which was to be held 11-12, has now been moved to...

ANONYMOUS wrote The sender and receiver of messages need to agree of two things - what data is being exchanged (the 1s and 0s), and - how many bits are arriving The 1st requirement is met by using encoding schemes that use the amplitude, or change in a...

Thank you; I've added these to our Resources page https teaching.csse.uwa.edu.au units CITS3002 resources.php

ABC News - "Explore the most important infrastructure you've never heard of the plumbing of the internet" https www.abc.net.au news 2024-03-06 the-cloud-under-the-sea 103137378 See also https www.submarinecablemap.com

https www.itnews.com.au news nbn-co-wants-to-boost-its-100-20mbps-tier-to-500-50mbps-605754 "NBN Co will today unveil a plan to change the top three speed tiers for residential broadband by the end of the year for users in its fibre and hybrid fibre...

And - List of 2024 Leap Day Bugs https codeofmatt.com list-of-2024-leap-day-bugs

Yes, should be 6.1-6.2 Thank you.

Sanity restored - please 'go back' to the CITS3002 homepage for all webpages now.

Sure; if you're meaning the weekly Schedule (with the book sections), it's now here https teaching.csse.uwa.edu.au units CITS2002 3002 schedule.php

The problem is a weird one so, anticipating what files you'll all be seeking this afternoon and over the weekend, I've placed some copies elsewhere Lecture-1 https teaching.csse.uwa.edu.au units CITS2002 3002 lectures lecture01 01.html Labsheet-1...

Yes, blank for me, too. Have asked why as, for example, other units are OK, and it's only .php in CITS3002 that's coming up blank. Weird.

"Today is ... February 29. That's normally a quirky, astronomical factoid (or a very special birthday for some). But that unique calendar date broke gas station payment systems across New Zealand for much of the day." https arstechnica.com gadgets...

The Girls Programming Network https www.girlsprogramming.network perth is a great outreach activity which has gone from strength to strength since it moved to UWA last year. High school girls are guided through writing Python programs, and they ha...