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And, not least, about
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Weblog Archive Cutedge

by: Bernard Teo

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Copyright © 2003-2012
Bernard Teo
Some Rights Reserved.

Fri 25 Mar 2011

Downloading Xcode 4.0.1

Category : Technology/DownloadingXcode4dot0dot1.txt

There's a new Xcode version 4.0.1 for download from Apple Developer Connection. Just in time to try my new download speed.

Everything is working well so far with my new broadband plan. Except for one thing. I don't seem to be able to connect my Mac directly to the broadband modem anymore via PPPoE, bypassing the Airport Extreme Base Station.

I think I've tried everything - like switching off the modem completely to drain it of all power and to clear out any "memory" problems with the previous connection - but the Mac refuses to connect.

Just to make sure it's not just a Mac-only problem, I tried it also with the Singnet technician's Windows laptop. Was perversely happy to see that that didn't work either.

Maybe I need to reset the modem. Hadn't tried that yet. But that would mean bringing the site down again. Didn't want to do that.

Will try again when maybe I get a parallel duplicate broadband line that I can devote to doing such testing. I do have a Mio TV connection that could have its Internet connection activated - maybe with the new 200 Mbps optic fibre connection (that comes with a 100 Mbps upload path, so downloads from my site go that much faster). That may look like quite attractive but I don't think I can afford that yet.

P.S.: In the time I took to write this, Xcode 4.0.1 is already halfway downloaded, at my new 15 Mbps download speed. That's a 4.3 GB download. If I have a 200 Mbps line, that would all have come down in a jiffy. Whatever speed you have, you will always want more.

Posted at 6:48AM UTC | permalink

Tue 22 Mar 2011

More Wireless Speed

Category : Technology/MoreWirelessSpeed.txt

While I'm waiting for the Macs to all get up to 10.6.7, a couple of tech updates that might help some people.

Here's one about getting the best speed out of your Airport Extreme wireless network.

All my Macs are now capable of operating at 802.11n speeds and so I should be able to switch my Airport Extreme Base Station to work exlusively on the less crowded and much faster 802.11n 5 GHz space, right? And get 300 Mbit/s Link Speed for all my Macs instead of the anaemic 120 Mbit/s at 802.11b/g/n mode. Right?

In practice, it's not so simple. It should be and one day it'll be but now it's not.

That's because, if you switch the Airport Extreme Base Station to the 802.11n 5 GHz range, you will find that some of the Macs will mysteriously lose contact with the base station's network when they come out of sleep or when they restart. All my Macs do that except, fortunately, the new Thunderbolt early 2011 MacBook Pro.

I spent a few days tracing this and found that it coincides with the Airport cards in the Macs thinking that they have a different country code from what they should be, e.g., DE or TW instead of SG in my case. When this happens, they can't find the Airport Base Station.

So this makes some sense, because my Airport Extreme Base Station's country is set to Singapore and this probably determines the range of frequencies or channels the base station would use. If the Airport card on the client Mac thinks it's operating in a different country, that will set that airport card's operating frequencies and these two - the range carried by the station and the one listened to by the client - may not coincide and that would explain why the client Mac can't find an obviously operating Airport base station.

So the question really boils down to, why does the Airport card randomly think it's operating in a different country (from what it should most obviously be) when the Mac comes out of sleep or when it's been rebooted?

The answer is, if you'll search the web, it's not random but it's definitely a bug. It's not random because the wireless cards of the world, and not just the Airport cards, determine the country code from the first operating beacon that they encounter and not just the base station that they're supposed to tune in to. So among the 2Wires and Linksys in my neighbourhood, there are many that still think that they're operating in Germany (DE) or Taiwan (TW), because their owners neglected to set the operatng country parameter correctly.

This is what happens when you give people too many buttons than they know how to press or too many options than they know how to fill in. This is the PC-everything-and-the-kitchen-sink mentality that is the blight in the neighbourhood.

The new MacBook Pro seems to have that bug fixed because it always (or maybe, mostly) gets the country code right when it comes out of sleep. But the other Macs need some help. I've determined empirically that the country most of the Airport cards think they are operating from, when they come out of sleep, is DE, probably because of the preponderance of PC-type wireless routers that have their operating country left as Germany in my neighbourhood.

In the Aiport Extreme Base Station, you can select a specifc channel to use in 802.11n 5 GHz mode, overriding the default choice ("Automatic"), if you hold down the option key while clicking on the pop-up menu. I've set the channel to 36, which is one that is used both by DE and SG.

And this has solved the problem. So I get all my Macs now operating at 300 Mbit/s over our Airport network. And things like file transfers feel that much zippier.

End of a happy story? Mostly. But occasionally, a rogue router that thinks it's in Taiwan will pipe in with TW please, before the DE's could respond and the Mac that is so stupid to listen to it will lose contact with the Airport base station (because TW doesn't operate with the channel 36, that DE and SG do). Usually for me, that Mac is an old MacBook that my kid uses and I've taught him to turn off and on Airport to get that out of the way because DE usually prevails here.

It's definitely a bug. It seems to have gone away with the new MacBook Pros. Apple should provide a firmware update to fix this for the older cards. Otherwise people will be operating far below the Nirvana they have the right to attain, just by being smart enough to use a Mac, or an iPhone or an iPad.

Posted at 8:17AM UTC | permalink

Mon 21 Mar 2011

More Speed

Category : Technology/MoreSpeed.txt

I'll be upgrading my broadband line to 15 mbps on Friday. I'm currently on 10 mbps but I'm only getting about 6 mbps when doing the speedtest. So I thought I'd better find out where the bottleneck is, otherwise I'll never get the 15 mbps that I would be paying for.

Turns out it's the broadband modem.

I've been using an old one from Efficient Networks, called the SpeedStream. I replaced it today with the Aztech DSL1000ER and I get the 10 mbps now.

So why did I live with this limitation for so long now? It's mainly because bridge modems as so hard to find.

I hate the PC-centric modem-cum-wireless-router (plus the kitchen sink) ones like the 2Wire, etc, because they're so hard to configure. It's all so easy with the Apple Airport Extreme Base Station. So I always need only a dumb bridge modem, where the configuration is all done on the AEBS.

So I found the Aztech. It's true plug-and-play, straight out-of-the-box, with the AEBS, no configuration required on the modem. Actually the DSL1000E model is good enough. But I could only get the DSL1000ER in Singapore, which I purchased from the Singtel Helllo store.

P.S.: If you've been coming here the last few days and found the site down intermittently, this was why. I've been experimenting with a whole lot of modems.

Posted at 1:27PM UTC | permalink

Fri 19 Jan 2007

AEBS Hanging - Theories and Hypotheses

Category : Commentary/NAT-PMP.txt

Just an update to the mystery of my Airport Extreme Base Station hanging since I've got my new MacBook Core 2 Duo.

I've tried almost every combination of Channel, Mode, and Multi-cast Rate using the Airport Admin Utility. I'd thought that I had hit on a certain combination that will work but I still found the base station hanging after a week, and so out went that particular theory.

So I'm putting forward another theory, namely, the hanging is caused by the use of the NAT Port Mapping Protocol (in Airport Admin Utility):

in conjunction with the use of automatic .Mac syncing in Systems Preferences:

I've tried almost every idea, so why not this?

The NAT Port Mapping Protocol option is new - it only appeared with the V5.7 Airport Base Station update. It is there to help make .Mac syncing go faster when you're syncing more than one machine on your local network with .Mac, behind your router. I've had that turned on since doing my last Airport Base Station firmware update.

I've had automatic .Mac syncing turned on only since I had the MacBook Core 2 Duo. For me, .Mac syncing alone is worth the subscription cost of .Mac because I change my development machines often. So after I had that effortlessly smooth transition to the new MacBook, I thought - why not make syncing automatic.

My theory is that some confluence of events relating to the use of the new Airport Extreme card in the new MacBook, together with NAT-PMP, together with the possibility that a sync was in progress when I decided to end a work session, caused the Airport Extreme Base Station to hang moments after I've closed the lid of the MacBook.

Now all this is just theory, not being able to debug the code in the Airport Base Station. The theory will die a natural death if the Airport network hangs in the next few days. But it's been a week now. So we'll see.

But the point is : that's what we programmers do all the time - formulating theories. I've often been hit with despair when my own software application keeps on crashing randomly, and it seems there's no way to figure out why except to pray to God. But what I've learnt is this - the way to solve it is to keep on generating theories - and have the ability, and stomach, to keep on testing them.

Writing good software is hard. That's why I'm willing to give the Airport engineers some slack and try to find ways around a possible bug - the alternative is to believe, as has been suggested when you do a Google search on this problem, that the base station is reaching the end of its useful life. If it survives another couple of weeks without hanging, I'll be prepared to believe that rumours of its impending demise had been greatly exaggerated.

OOps, I forgot to mention that the solution I'm trying out is to turn off the NAT Port Mapping Protocol option in Airport Admin Utility.

Posted at 1:10PM UTC | permalink

Mon 01 Jan 2007

The Ghost in the Machine

Category : Commentary/poltergeist.txt

I'd better scratch that last advice I gave about Airport Extreme Base Station (AEBS) settings. To recap, to improve the wireless reception that my MacBook Core 2 Duo is getting, I set the AEBS wireless mode to "802.11g Only", which did provide the MacBook with a consistently strong signal.

But the downside is : I found the base station hung up three times in the last three days.

The strange thing is, the base station hung up each time moments after I've closed the MacBook and put aside my work. The first time when I left to attend a funeral wake (eerie!). I was away for three hours, and that's how long our server (which sits behind the base station) was down. Fortunately that happened between three to six in the afternoon (our quietest period in a 24 hour cycle) so maybe not that didn't stop too many people from accessing the things that they want.

Then the next time was, after watching Man United beat Reading on Saturday night, I answered the last of the mail I had still pending, went to sleep, woke up at five (I'm an insomniac) and found the base station hung minutes after I had gone to sleep. I can check, using WebMon, when the last hit on the server had occurred. The site had been down another three hours.

At this point, at five in the morning, I'll admit I was open to any suggestion that a poltergeist had somehow followed me home and was watching my every move.

Then yesterday afternoon, I wrapped up some work for the year and went for a run. You guessed it! Almost two hours later, when I got back, I found the base station hung, almost to the minute I had left the house.

Now, if we have a poltergeist in the house, that must be some Internet TCP/IP-savvy ghost.

Not willing to give in to superstition, I've reset the base station settings to "802.11b/g Compatible" and everything else (channel and multicast rate) to the defaults, to see if we'll get another crash.

But that's, of course, superstition on another level, because I don't at all understand what all these settings do, unlike when I'm debugging my own code and I can find exactly the explanation for why things work the way they do, no matter how seemingly random. "When you believe in things you don't understand, then you suffer", so says Stevie Wonder. But life is lived among varying levels of illusion.

One man's superstition, another man's religion.

The title comes from The Ghost in the Machine by Arthur Koestler, which together with The Act of Creation and The Sleepwalkers, are three great books about the history of technology and the origin of ideas.

And a Happy New Year to all. It is the new year, at last.

Posted at 9:44AM UTC | permalink

Fri 29 Dec 2006

Airport on MacBook Core 2 Duo

Category : Commentary/AirportExtreme80211g.txt

I was having terrible Airport reception from my MacBook Core 2 Duo, when accessing an Airport Extreme Base Station. The reception was poor, wasn't steady, often wavering, and it even lost connection entirely now and then. Applying the latest Airport Software Update didn't seem to have any effect.

Then I thought of switching the Airport Extreme Base Station to use only 802.11g with a multi-cast rate of 6. Now, changing the multi-cast rate was probably voodoo/superstition, because I don't quite understand the effect that was having, but using 802.11g exclusively seems to have fixed the problem for me.

I've got another broadband line with another base station on 802.11b, for my older iBook and PowerBook. Strangely, my MacBook had no problems whatsover attaching to this base station, which is built into a SpeedTouch modem/router, and works only on 802.11b. That was what gave me the idea of switching the Airport Extreme to work on only one setting rather than supporting both simultaneously.

Also, I couldn't have debugged my problems with PayPal yesterday without this other broadband line and the spare server that I've hooked up to it. I created a new PayPal account using my wife's email address and set up a domain that I own, called, and in a short while I was able to start making on-line payments to it. And that PayPal account is easily linked to a local bank account. So theoretically, I've shown I'm able to set up an on-line Internet business in minutes.

Now that I've got this set up, it allows me to see if I can package this payment processing system that we have into something more robust that other people can download and use. That's going to be one of the projects for next year.

Posted at 6:04AM UTC | permalink

Sun 24 Jul 2005

Airport Extreme Base Station Firmware Update

Category : Technology/AEBS551.txt

There's a problem with the Airport Extreme Base Station Firmware Update 5.6 that prevents the base station from connecting to the ISP over PPoE.

It's not consistent. An AEBS updated to 5.6 continues to work with PacNet but fails with Singnet.

I managed to find the previous 5.5.1 update at the Apple site. After loading that in, the Base Station works again.

For a while I thought I had lost a base station. Avoid the 5.6 update if you can. (Actually, avoid it like the plague.)

Posted at 10:02AM UTC | permalink

Sun 17 Jul 2005

Airport Base Station Firmware Update Warning

Category : Technology/AEBSFirmwareUpdateWoes.txt

I've tried to connect my "old" Airport Extreme base station (the one that went PPoE dead after the firmware 5.6 update) to the broadband modem and again it fails to connect to PPoE. But it worked fine at Hai Hwee's house after a hard reset.

So now, I'm not sure if it has somehow acquired an incompatibility with the Efficient Speedstream 5250 ADSL modem or is it with Singnet itself. Hai Hwee's house is on PacNet, using an Aztech DSL 305E modem.

Anyway, this is a warning for Singapore-based users. Think twice before you do that 5.6 firmware update.

Posted at 8:29AM UTC | permalink

Fri 14 Nov 2003

PacNet blocks ports 995 and 993

Category : Technology/PacNetSSL.txt

Following on the previous posting, I think I was wrong about the Airport Extreme Base Station. It was my ISP that was blocking ports 995 and 993, for whatever reason they had, and that was why POP and IMAP over SSL didn't work.

I took the Airport Extreme Base Station out of the equation by connecting the server directly to the broadband line and SSL still didn't work for POP and IMAP. So I can't blame the base station, though I guess I've still got to do a test that will prove conclusively that the Airport Extreme Base Station will channel the SSL ports in correctly. So, the situation is, if I don't have a bug in the latest version of Postfix Enabler (1.0.4), POP and IMAP over SSL will work most of its users.

Posted at 1:07PM UTC | permalink

Airport Extreme and IMAPS and POPS

Category : Commentary/IMAPSPOPS.txt

I've discovered that the Airport Extreme Base Station does not pass ports 993 (for IMAP over SSL) and 995 (for POP over SSL) through even though I've set port mapping on.

I've noticed this before when I got POPS and IMAPS working on a home machine that had the old Airport Base Station, but not at the office where we have an Airport Extreme.

But, then again, it be could be due to the different networks I am on - one on PacNet and one on SingNet. But I don't think so. It's probably the base station. I need to do a test again tonight to prove this conclusively.

Which brings me to the point of this whole weblog. Even when you try to make everything work smoothly (a click here and a click there), you're still going to get hit by blocks like these. A lot of the opposition to the Mac from the IS perspective comes from the belief that the Mac would eliminate IS department headcount. How do you spend your days when you're not going to be busy troubleshooting system failures?

My point is that there is a whole lot of stuff we can spend our time better on - like how do you organise the business workflows, how do you account for things so that you know if you're making money or not? All these use IT but you're working on things at a higher level. The whole point of driving your way quickly past all the low-level SMTP, sudo, /etc/xinetd stuff is to get to this top-level view fast - before the business gets eaten away by the competition.

In case this is overstating things, we need to remember that a programmer or graphics artist in China (or India) is happy making S$400 a month (that's like $250-plus in US dollars). That's why a friend of mine can do a pretty nice business bringing work out to China. You can be sloppy sizing a project, and let it overshoot by three months and still make money. It's a tremdendous cost difference. That's why we want things to just work. That's why we use the Mac. It's not because we love Apple. It's because there's no way out but to compete - but we've got to choose our tools well.

Posted at 3:59AM UTC | permalink

Thu 07 Aug 2003

Sendmail SMTP-AUTH

Category : Technology/smtp-suth.txt

I'm just re-surfacing after diving into the murky depths of the beast. For there is no other name for sendmail. It's a beast of a system.

But I'm amazed I could even compile sendmail from source. So, now I've got a version of sendmail with smtp-auth that works. And I know how to put that in, in place of the stock sendmail version that comes with OS X, and also how to take it out.

And I also know enough how to put in Postfix, swap out sendmail, and do the reverse.

And, I can confirm that the version of the pop server I bundle with Sendmail Enabler does SSL. I'm still having some problems with the Airport Extreme Base Station, but it works beautifully when it's sitting behind the original base station. If I can figure out how to set up the certification stuff with just one click, you can pull your mail down from the POP server under SSL

So, a summary. Even though I can do smtp-auth, I'm wondering what's the point? It was meant to make sure that people on the move can always get back to the home server to send out mail, because that's what smtp-auth does - it authenticates the user before authorising the user to send mail. But, if you make authentication a requirement (otherwise it makes no sense to have it), it creates a downside - this server can now only send mail out. Another mail server that is trying to send mail to this server probably won't know how to authenticate itself to this server. So you end up having to set up two servers, one for sending out mail and another for receiving mail.

But with Sendmail Enabler, people on the move can enable sendmail on their PowerBooks to send mail out themselves. They only need to go to their home server to receive their in-coming mail. For added security, this takes place under SSL so that all the communication is encrypted. They've always had to authenticate themselves anyway when they're retrieving mail.

So, I believe that's the optimal solution. Freed from the need to act as a relay for roaming users, the home server can be set up with the tightest of security, including a variety of strategies for blocking spam. Also, you get a freer hand to tie the workings of the mail server with back-office e-commerce applications - there are variety of hooks in sendmail to do that - since most of the users are sending mail out directly from their own workstations.

I had a concern that Sendmail Enabler could have made it even easier for spammers to equip themselves with their own spamming engine. But, if you free your mail server from having to relay anything from outside your local network, you cut off one source of free bandwith for the spammers. You can't stop them from trying, but at least they're being pushed back to use their own bandwidth. You can, however, put in all the blocks you can muster to kick them out before they can even come into your network. And you can do it better if you don't have to make allowances now and then to let in one of your own guys to use the mail relay. If this works, Sendmail Enabler could have changed the rules of the game - at least for the Mac-speaking world.

Posted at 4:48AM UTC | permalink

Thu 19 Jun 2003


Category : Technology/fairport.txt

I got a NetGear wireless PC card for our Dell laptop today. It's a snap getting it to work. It recognises our Airport Extreme Base Station and (whoosh!) we're surfing the net on the Dell, no strings attached.

It's interesting what the guy at the PC shop said when I asked if the card's known to work with the Airport Base Station. He said, "Yes, but the PC can only surf out; it can't talk to the Mac and vice versa." I asked him what makes him so sure. He admitted he's never used a Mac. So I told him that, if it can surf out, it'll talk to the Mac. Now it's me who's sure.

In fact, that's what happened. Share a folder on the Mac and the PC can see it. Share a directory on the PC and the Mac can see it. It's the magic of OS X, which gets better and better all the time.

Posted at 4:00PM UTC | permalink

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Put your Mac to Work Now how would you do something like that?

Weblogs. Download and start a weblog of your own.

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A Business Scenario
How we could use Macs in businesses

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