Computers

Such speeds are quite easy to achieve in BitTorrent, in an almost stock configuration with BitTornado client, with encryption turned on.

I’m always wondering, why people keep talking about ‘settings’, for more decent speeds. I mean, there’s hardly anything you can tweak in the client that can give you speed boosts in the range of 100 kilobits and more. My hypothesis for their poor speeds is that they have poor hardware and network setup on which the BT client runs.

I mean, it is rather common to hear BT clients running behind a consumer grade router, NAT’ed, conntrack’ed and all, but with very little memory and processing power on these embedded devices.

So really, rather than the magic set of setting combinations, bottlenecks along the way such as tracking table sizes and modem capabilities should be ironed out. A quick and easy method is to use a professional-grade router. Or just replace the router with any micro-computer with sufficient amounts of RAM. Anything with 500MHz and more than 256mb of RAM can be an extremely powerful router for the home consumer. After all, the biggest bottleneck lies with your upstream provider and bandwidth.

Only after which, one can then start with the art of managing one’s upstream bandwidth.

The idea is this, (from my experience) leave at least 5 kb/s of upload bandwidth unused to allow for spikes, above and beyond the allocations by the QoS protocol and the calculated reserve bandwidth (more on that in a while). Generally, for every 15 kbps of download, there needs to be 1 kbps of unused upload bandwidth (8 kbps = 1 kb/s).

Based on the above ratio of 15:1, assuming you’ll want to achieve 1500 kbps of download speed, you will need to have 100 kbps of upload bandwidth available, not in use by BT or anything else to upload data.

To find the optimum setting for ‘max upload speed’ in the BT client, find your maximum download bandwidth, divide it by 15, and you’ll get the reserve upload bandwidth you’ll need. Then take your maximum upload bandwidth and minus your reserve upload bandwidth, and you’ll get a ‘max upload speed’ value for your BT client.



Once you’ve got your bandwidth ratios worked out and balanced, you can then proceed on to tweak the max open connections and the max number of running transfers limits. The values of the above two keys would largely depend on the type of router and modem you’re using.

Started some days back, the flood of co-ordinated, distributed but slow brute-force attempts on my sshd (and possibly others) was evident in my logs. Over a few days, my logs swelled into megabytes, many times over the usual kilobytes.

The attack, I have to say, was rather intelligent. The attacker(s) used many machines, each trying a name starting from a, in concerted succession, alternating one after another. This way, my usual brute-force detection systems fail to kick in as they are seen to be a few invalid logins from each host, when view in a per-host isolated context.

In clearer terms, let’s say there are 1 to 1+n hosts. Host 1 tries to login as a. Fails, wait 1 second. Host 2 tries as b. Fails, waits x seconds, where x < 10 seconds. Host 3 tries as c. Rinse and repeat until the whole dictionary is visited. Innocent as each individual login might seem, when view from the context of an attacker, it’s simply brilliant.

Believe it or not, eventually, it’ll enter my machine if my defences aren’t stepped up to at least trigger a reaction to these events.

Days before, I’ve already implemented login tallies, whereby whenever an user account has experience 3 consecutive failed logins, the user account is locked, regardless of the password supplied. This way, I get to control when the accounts are re-enabled, allowing me to keep a closer eye on the situation.

Coincidentally, while the attacks are going on, one of my friends told me about his account which is always being locked out. As I was away from home, except to sleep, for the large part of that week, I hardly had the time to investigate.

Two days ago, in a bid to improve security, I came across this great defence mechanism, Fail2Ban. It works for multiple services and can flexibly do anything whenever too many failed connections are detected.

I rushed down to Funan after work, hoping that I could get my hands on the Company of Heroes Gold Edition which also comes with the Opposing Fronts standalone expansion pack.

I visited numerous shops but all of them claim that the product is sold out. Then, I came across ‘GameSpot’ and looked inside. To my horror and surprise, they have the product on stock, but only at S$19.90. I clarified with the staff as it looked like a misprint – too affordable to be true, compared to the standard retail price of S$59.90. The price was right, and I bought it.

At S$19.90, it’s a good opportunity to pay for a 2006 Game of the Year and play it online; it’s one of the best, if not the best Real-time strategy games I’ve ever seen.

This is probably what Apple meant when they say high-technology:-


It’s a flight simulator on the iPod Touch / iPhone. Review available here.

At 6.2 mb, this is a perfect demonstration of the true capabilities the Apple device is capable of.

Playing with my iPod Touch today, it suddenly occurred to me that this device is actually a multiple more powerful than my Tungsten | T Palm-powered device. This device has 8GB compared to 32MB in my palm; a screen 1.5 times bigger and brighter; and with two times the battery life and almost equal functionality. The only thing the palm device could do better is that it has bluetooth hardware. Everything else, including pricing, this Apple device triumphs; even 802.11g wireless.

Price-wise, the Apple device is half that of my previous Palm-device, at S$388. I bought my Tungsten | T 5 years back for roughly S$700.

Software-wise, given the recent release of the Singapore Bus Guide for the Apple device, this handly iPod is possibly on-par with the Palm at the height of its success.

Little did I expect, it is Apple, Inc. that surpasses Palm, Inc. with an equally easy-to-use device at half the price and double the technology.

Historically speaking, looking at the past decisions of Palm and Apple through their respective valleys of deaths, Apple has taken the route not travelled while Palm has taken the route most recommended by commentators, Dvorak and the likes. It’s an extremely rare and compatible foil between the two companies.

Commentators have suggested, when Apple was on the verge of collapse, some of the following:-

• License its OS to other hardware makers
• Copy Microsoft’s Windows strategies
• Compete directly against Microsoft in IT markets
• Split into hardware and software companies
• Buy Be, Inc. for its BeOS
• Adopt the Linux kernel
• License Windows from Microsoft

Those advice is what Apple has not taken but wholly adopted by Palm.

Look at the difference now: The Egregious Incompetence of Palm.

In other news, the iPhone is sold totally unlocked and contract-less at Apple Store Hong Kong, online, at ~S$1000 for the 8GB edition.

Lately, I’ve just started playing this game called Sudoku and found it quite interesting. As usual, the first thing that comes to my mind when I have a rough idea of how a game works is to code an algorithm to solve the puzzle using a computer.

There are a few approaches to this problem I can think of so far. The easiest and slowest of all is the brute-force iteration method. Just sub in a number, check if it contradicts any rules, and move to the next box, with a whole decision making tree of what to do upon alternative situations.

The second approach is by elimination. Fill up all the blanks with all possible but legal numbers. Through the checking of rules in a circular method from the centre, alternatives will be eliminated and most puzzles can be solved.

The third approach, the hardest and most interesting, is by inspection. By “visually” inspecting how set numbers are placed in a gird, reference to the rules of the game, some solutions are obvious and can be easily solved. The greatest challenge is to let a linear piece of code “read” the grids and say, “this looks like the only possible solution here”.

I shall think a little more about the data representation schema before starting work.

Python sounds like a rather good language to use...

2 years ago, I was handed a Dopod M700 running the latest Windows Mobile operating system then, 5.0. My experience was beyond terrible that I had to stop using that phone after a week as it could barely keep up with my usage style, brought over from my previous phone, a Sony Ericsson K610i. As a brief background about this smartphone, it is a huge touchscreen with a scrollwheel and a few utility buttons.

The first problem which I attribute to the fault of the OS is that I spent most of my time launching task manager, killing software that should not be running when they are not the foreground process.

Secondly, I spent and unwieldy amount of time attempting to launch software via its “Start” menu.

Thirdly, my contacts were in such a messed up state that I wasn’t able to contact anyone. As it only supports ActiveSync, Mac support is totally out of the window (pardon the pun). Having seen how Outlook behaves, I don’t exactly want to fathom what it’ll mean to my contacts.

Fourthly, pressure-based touchscreen is a pain to type with its tiny virtual keyboard. You’ll need to keep fingernails just to accurately touch something.

Fifthly, the ringer settings are beyond primitive that it doesn’t feel like a phone.

Sixthly, I can’t switch the usability feature on as I can’t find it!

In all, the device software feels more like a PDA with the phone functionality added as an after-thought. Really, if there’s anyone who claims WM OS is usable, I think he doesn’t understand what usability is. Many would also claim that the new version of the OS is better but I’ll beg to differ. Unless Microsoft redesigns the OS from scratch, it’ll still be a desktop metaphor crammed into a tiny screen.

Listening in forums about the iPhone, many claim that they prefer other ‘touchscreen’ phones such as LG’s or Samsung’s, etc, whereby all but one fail to consider or realise the difference in their touchscreen technology.

iPhone and the iPod Touch uses a capacitance-based system, where it is “skin-activated” rather than pressure activated. As such, just tapping with your fingertips would produce a result. On the other hand, most other touchscreen phones employ a pressure-based touchscreen system, where a precise and pressured point is required to register an input. Moreover, most pressure-based touchscreens are confused when the size of the pressure point increases. Thus, the usage of fingers rather than fingernails on such touchscreens result in poor recognition. A stylus is therefore usually provided.

This tiny but distinct difference is huge enough to affect usability experience to the extent that it makes or breaks “typing” on the on-screen virtual full-sized keyboard. This also explains why critics of the iPhone claim that it is impossible to type on the iPhone virtual full-sized keyboard as they fail to realise the subtle difference in technology employed.

In my opinion, the capacitance-based touchscreen system is worth more than enough to compensate the apparent “software fixable” cons such as the lack of MMS, cut and paste, email attachment support.

The only problem thus far is the built-in battery with a three-digit replacement figure.

I’ve been observing the prices that SingTel sets since the release of the product in Singapore and managed to gain a few interesting insights.

In the beginning, iPhone 3G (8GB) sells for S$598 with the Classic 100 plan. A week later, the pricing of this plan is removed from their advertising literature and subsequent calls to 1626 reveals that the price has been raised to $658. Next, iFlexi Premium plan does not come with a $300 handset voucher annually, due to “generous data and voice bundle”. Speculatively due to high demand, it was reinstated.

A new Broadband on Mobile plan, called the Plus, was created at the speed of 3.6 mbps with free data worth 500 MB at $19.90 monthly. A current Broadband on Mobile 1000 plan at the speed of 1 mbps with free data worth 50 GB costs only $22.42 monthly. With a 12 month subscription, there will be a 30% off, putting the price at $16 monthly.

I’ve done rather elaborate thinking on why such inconsistent plans such as the iFlexi plans are made and have yet to find an answer. I might be able to do so if I can have a feel of the take up rate of those plans. Furthermore, their FAQs regarding this question doesn’t exactly answer the question satisfactorily.

My calculations show that the iFlexi plans costs almost the same as the corresponding iPlans with great bandwidth but sacrificing a few magnitudes of free local data allowance. The cheapest so far would be a Classic 100 plan with BBoM 1000 at the 4th year loyalty tier at only ~$44 a month. The downside is that you’ll need to fork up a hefty bundle of cash upfront.

Hence, it will be imperative that would-be buyers do their sums first before signing up for these rather expensive plans.

I’ve learn a few things about AppleCare and how it basically works in the whole AASP ecosystem. A few weeks ago, I sent both of my Macbooks in for repair for various issues, ranging from bluetooth malfunction to bloated batteries.

A mistake I’d made was that I failed to contact AppleCare before I sent my machine down for repairs.

According to the AASP, the replacement of my bloated battery has to depend on Apple’s approval and there’s no guarantee that the (optional) replacement is free of charge. Exactly as they say, they messaged me a few days later claiming that Apple has refused to replace the battery and that I can purchase a new one for S$208. Based on my past experiences with AppleCare, I knew this isn’t usual and I thus declined to pay for any replacement, leaving the battery at that while I find time to contact AppleCare.

Yesterday, I finally managed to contact AppleCare and indicated the issue of a bloated battery. Upon confirmation that the battery is operationally fine but bloated, the support representative offered to replace my battery without much hesitation.

Well and good. Then, I checked my repair logs of the machine and realised that it has exceeded the magic number of 3. Gladly, I prompted the agent to check what was changed in the machine when I last sent my machine for repairs and he too noted the repair count and informed me about the replacement policy.

Well and even better. I got a new case number and am to call AppleCare again during their Australian office hours so that I can get this expedited through their customer relations department. That lies the royal trouble. I’ve got no time to call AppleCare between Monday to Friday, 9 am to 3 pm.

I guess, there’s no harm waiting as new revisions of Macbook would be released real soon.

The bottom line is this: Always call AppleCare first for any hardware related issues before bringing it down for repairs for a greater and less frustrating experience.

Come to think of it, I don’t mind getting replacements yearly now that Time Machine is working so well.

Got a 8GB iPod Touch as a prize and managed to finally jailbreak it with the 1.1.4 firmware, with January Features update.

Although the jailbreak is meant to be pretty easy, conflicting and outdated guides wasted a lot of my time. I’ve found the easiest solution to jailbreak an iPod Touch 8GB running 1.1.4 firmware.

That aside, with Wireless@SG up and running almost everywhere, the iPod Touch is really an awesome mobile device. The iPhone will be even better.

Today, I spent one of my long weekends doing some computer maintenance shopping. Although the computer systems in my house need little maintenance, still new technology should be acquired once in a while to make things look good.

Thus far, over the course of this year, my family bought a Samsung colour laser printer for $299, a pair of Homeplug AV devices for $207, and 2 external harddisks to sustain the Time Machine setups.

Next up to be purchased would probably be iMacs to replace my 7 year old desktops, Apple Time Capsule to bring my wireless network to the N generation with Bonjour printer sharing, modernising ancient but working technologies in my house.