It appears that my timing could be impeccable! The BBC has reported that Vint Cerf, who recently stepped down as chairman of the Internet Corporation for Assigned Names and Numbers (ICANN), has warned that ISPs need to roll out the ‘next generation’ of net addresses before the current IPv4 addresses run out. This date was reported as being 2010.

The full story can be read here.

After all the trouble I had with ns-2, I’ve gotten round to reading my first paper. It was an interesting read, but I felt it was a bit thin on content. I’ve gotten used to the idea that academic papers tend to be on the dry side, but all the advice I’ve had thus far is to persevere. So it was with a certain relief that I found a paper that was easy to read!  A summary of what the contents along with a brief critique is below.  One down, eight to go!

Clincy, V. A. and Mudiraj, P. 2006. The future leading mobility protocol: mobile IPv4 OR Mobile IPv6?. J. Comput. Small Coll. 22, 1 (Oct. 2006), 197-203.

The paper looked to evaluate both MIPv4 and MIPv6 so as to give an opinion as to which protocol would be the ‘Future Leading’. What the article failed to comment on was the fact that the world is fast running out of IPv4 addresses which may have an impact on its suitability as a ‘Future Leading’ protocol.

The paper gave a brief overview of the key differences between the two protocols:

  • MIPv4 requires the use of a Foreign Agent
  • MIPv6 uses Route Optimization (sic) for improved performance
  • MIPv4 uses ARP
  • MIPv6 uses Neighbour Discovery
  • MIPv4 uses a directed broadcast approach to discover the Home Agent
  • MIPv6 uses anycast and receives a single reply

The paper mentioned that one of the key aspects of performance is in the handover from one access point to the next whilst a mobile node is moving. The details of this differ from MIPv4 to MIPv6. It is worth mentioning that IPv6 has had Mobility in mind since inception.

My chief criticism with this paper is that the comparison experiments were limited to two scenarios but neither used both protocols for a fair test. As mentioned before, both IPv4 and IPv6 implement Mobile IP differently. The scenarios were:

  • Wired Mobile IP network using Mobile IPv4
  • Wireless Mobile IP network using Mobile IPv6

Surely it would have made sense to at least run MIPv4 and MIPv6 across a wired and wireless Mobile IP network?  Also the chosen metric to assess the performance was the end-to-end delays.  No explanation was given which would have been insightful.

Finally there was some data supplied which suggested that MIPv6 is more efficient at routing information as a result of there being no foreign agent and the Route Optimisation strategy.

So in summary, I didn’t learn much more than I’d already found out from books and in the end, the paper didn’t commit to what the authors felt was a ‘Future Leading’ protocol.

I’m still experiencing setbacks with relation to the installation of ns-2 and also the Mobiwan extensions for Mobile IPv6.

Here’s the current situation:

  • I’ve been unable to install the following on my Laptop under Ubuntu:
    • ns-2.26
    • ns-2.27
    • Mobiwan extension for Mobile IPv6 for ns-2.31
  • I’ve been unable to install the following under Windows (with Cygwin)
    • ns-2.26
    • ns-2.27

The only option left to me, short of suggesting an alternative simulator, is to ask Support to install ns with the Mobile IPv6 extension on my behalf. This isn’t an ideal situation as I’d prefer to be able to use my own machine and not rely on the SoC computer provision.

So, not much forward movement at the moment, but at least it still (relatively) early days.

For my final year project, I am going to use a network simulator simply called ‘ns’. In order to simulate Mobile IPv6, I need to install the Mobiwan extension that has been written for ns by Thierry Ernst.

Unfortunately, it was last updated in December 2004 and only works on an older version of ns. (I’d already tried applying the extension to the latest version, ns-2.31 with no luck). This already had alarm bells ringing and so I set about installing the older, compatible version, ns2-27. However, there were some installation issues that as yet I am unable to resolve. I’m presently trying to run ns under Cygwin on Windows, but I’m not entirely confident that this will work either.

This leaves me with a few choices:

  1. I persevere and install ns.
  2. I use an alternative network simulator.
  3. I change the scope of the project.

Given where I am at in relation to the project, option 3 is out, and I’ll need to consult my Supervisor over option 2 so for initial time being, i might as well continue with option 1.

An update to this will (hopefully) appear later today.

I’ve managed to find nine seemingly relevant papers through the Web of Science, seven of which I’ve printed out. I’ll now spend the next few days reading them and trying to ascertain what it is they have and haven’t done, and what I could do different and/or better. This seems to be the challenge! I also need to get ns-2 installed on my home machine although with the latest release of Ubuntu 7.10, I’m worried about compatibility issues. I’m sure someone will be able to put my mind at ease on this one (paging Dr. O’Shea…).


I have just been using the Web of Science database which can be found through the University’s library page,, and thus far it’s turned up several papers relating to Mobile IPv6 and specifically simulation and performance. The next stage is to go through the papers and ascertain what useful nuggets of information I can find.

Karim, my supervisor, mentioned to me that I need to also find information regarding other simulators so as to justify the decision to use the ns-2 network simulator. This might prove to be more difficult as I can’t think where I would find the kind of information that would allow such comparisons. I guess a good starting point would be to do a search with Google for ‘network simulators’ and then visit the websites of the differing programs.

I may need to find better sources of information for my report however…


Good afternoon! It’s a lovely Saturday afternoon in November and probably a little warmer than I would expect it to be!

Some of my friends are also doing final year projects and it had been suggested to them that they blog their experiences to keep a record of what goes on. With this in mind, I decided to do the same. It will hopefully prove useful not only when writing the personal reflections section of the report, but also give me an idea of what I was thinking about at a certain time. In other words, my memory is good, but not that good!

If you decide to follow my progress and wish to comment, please do so and hopefully it’ll help me in some way. I’ll also try and link to some blogs operated by others so you can see what they might be up to.

In the meantime, I hope you’re all having a good weekend thus far!


Attendance in advanced graphics on Thursday was particularly poor, in fact a mere 16 students turned up. This may well be due to the fact that some had spent all night previously completing coursework, but really thats not much of an excuse. Advanced graphics at the school of computing is one of the hardest modules you can take in the third year and I wouldn’t want to be missing any lectures, certainly not on a whim anyway.

Its amazing how much you can miss in just one lecture. On the few occasions I have had to legitimately miss a lecture its taken me nearly twice the duration of the missed lecture to catch up on all the work and in a pressured environment like the third year of a degree course I can’t understand how anyone has the time to perform such a catch up. I’d like to suggest that the simply don’t, in which case more fool them come exam time when they’re scratching their heads.

On the plus side if not many people attend then those that do get more interaction with the lecturer when it comes to asking questions and such which is clearly beneficial. It was certainly true that on Thursday those who attended managed to get a lot of our questions answered. Perhaps I actually like there being less people in the room.

On Monday and Tuesday this week the university are holding a careers fair. This is the first point in my university life where I really feel like attending such an event, not to mention feeling that it would significantly benefit me, what with being in my third year and all. Only problem is I have a solid day of lectures on both of the days.

This is just sods law at its best really. I mean of the 2 days they hold a huge fair I can’t go to a single hour of the 8 on offer in total. Luckily the major players in IT do visit the school of computing specifically, but its really not that brilliant that I have to miss out on meeting representatives from companies that won’t. If it had been any other year I’d probably have missed the lectures, attended the fair and caught up on the work later but being third year I really don’t wish to do this, nor do I think it would be advisable.

What I’d like to know is which person in the careers service organises these events without checking to make sure that the majority of third years can make at least an hour of the proceedings. Assuming they don’t miss lectures, I can’t name a single computing student who can go to any of the fair, and that makes a fairly large number of people missing out which one would imagine the careers service should endeavour to avoid.

There has been a lot of talk lately in the news about the potential for the implementation of a two tier internet, that is to say a global collection of networks in which some traffic is given priority over others, not necessarily for reasons of efficiency but for those of financial incentive - those that can afford to pay can prioritise their internet traffic or take advantage of less restrictive access to the content of others.

This is something I wanted to muse over a little before committing thoughts to my blog because it is something close to my heart. Having given it some thought though it is actually a less savoury prospect than I had ever imagined and I was never in favour of a two tier internet in the first place.

At present the internet is a place in which content is indiscriminately accessible to all; something I publish is available to a user in, say, Australia as readily as it is to someone who lives up my street. Likewise someone on a cheap ISP can also access my published content in exactly the same way as someone on a more expensive provider.

Two Tier Internet means that for the first time some publishers will be able to dictate which “class” of consumer will be able to access their content and what is worse even if the publisher intends to allow everyone equal access the ISP could be equally restrictive if it took their fancy. My internet might not be the same as your internet and this means that whole areas of the internet could be completely invisible to you without you even knowing it. Sure, you might be able to hit IP addresses but they would time out as if there was no machine responding if they weren’t on your tier.

I cannot stress enough how damaging this will be to the whole ethos of the internet. Tim Berners Lee (creator of the world wide web in case you didn’t know) said himself that the connections we use to share data should be freely accessible to all and that the whole way in which the internet works relies on us all being on one network in which we all have the potential to be equal players. If the very creator of the web intended us to have one internet and believes it would be damaging to split it up, why should legislators who have no technical knowledge have the right to say it shouldn’t be that way? Quite simply they are taking the piss.

I’m not going to jump on a high horse about the quality of the content I have to distribute to the world, especially since some of it is probably pretty crap in the eyes of some who might come across it, but I sure as hell don’t want to see someone else deciding who should see it or not based on who is lining their pockets. I put it online because I want everyone in the world with a connection to be able to read, listen to, watch or download it as they wish. If a day comes when I can no longer do that, the one place on earth where we are all still truly free, the internet, really will be dead and the world will be a much darker place.

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