John's Computer Support Blog - Internet

How to break the Internet

nospam@example.com (John Crowhurst) — Sun, 29 Aug 2010 00:14:19 +0100

Scientists from Duke University and RIPE managed to break 1% of the Internet by sending experimental data over the internet. The experiment used a new version of BGP (Border Gateway Protocol) that Internet Providers use to connect their networks to others around the world.

BGP is a big table that tells the routers how to get to a location and how many hops (each provider that is big enough to use BGP has a unique number called their Autonomous System or AS number) it will take to get there together with the cost to do so. A connection with the fewest connections (known as hops) works well for the protocol OSPF (Open Shortest Path First) but tends to be expensive, whereas it may be cheaper to do more hops.

By using some experimental extensions on the Internet, the routers couldn't cope with the new data. 3,500 of these hops over 60 countries ceased passing data.

The story can be found here

Satellite Internet

nospam@example.com (John Crowhurst) — Mon, 26 Jul 2010 17:45:11 +0100

Contrary to popular belief, Sky does not offer a Satellite Internet service. Sky offers Satellite TV with broadband being delivered over an existing BT telephone line.

Satellite Broadband is provided for places where there are no telephone lines or where the exchange doesn't offer the facilities for broadband. Countries such as Africa benefit from this technology.

Satellite Broadband is relatively slow in comparison to telephone delivered broadband (ADSL) or 3G mobile broadband and the hardware is usually prohibitively expensive. A dish will cost between 3-4,000 and monthly contracts start from around £50 per month.

The technology is pretty simple, you send a small upload to the satellite and then be prepared for a large download. The technology is practically useless for anything that requires real time communication, such as VoIP since it takes some time to send the signal up and down instead of over the wire.

Firefox brings in new feature

nospam@example.com (John Crowhurst) — Wed, 23 Jun 2010 12:59:14 +0100

In the latest version of Firefox (3.6.4) a new feature has been introduced called OOPP (Out Of Process Plugins) which means that the plugins run separately to the main program, so if your flash movie crashes it doesn't crash the browser.

Changes to site

nospam@example.com (John Crowhurst) — Sat, 12 Jun 2010 18:56:38 +0100

For a while I have tried using captcha, (Completely Automated Public Turing test to tell Computers and Humans Apart) where you type in the words that were generated in the box and it would allow you to send an email.

This kind of protection can be difficult to implement as well as being a chore to use.

I discovered a better one that involves moving the shape to a circle with the mouse.

So far I've seen no SPAM emails being sent to me, whereas I'd regularly see SPAM emails without it.

3G MicroCell

nospam@example.com (John Crowhurst) — Fri, 14 May 2010 14:04:31 +0100

AT&T have just revealed something they are calling a 3G MicroCell.

I've covered 3G to WiFi routers in the past, this is different in that you connect it to your home or business broadband and it provides you a 3G signal.

You can register 10 phones to the system and use up to 4 at any one time.

You get unlimited calls on your mobile phone when connected to their equipment

It gives you full bar signal and 3G network service in your own home up to 5,000 feet.

The technology is only available in the US at present, but I'm sure other telephone providers will follow suit soon

Travel Wireless

nospam@example.com (John Crowhurst) — Sat, 17 Apr 2010 21:16:13 +0100

I was looking on Solwise's website where I got my first broadband router from and noticed they are selling a travel wireless router.

The unit is palm sized and connects to a 3G dongle to provide both wired and wireless internet to your wireless devices.

BT exchange floods and catches fire

nospam@example.com (John Crowhurst) — Fri, 02 Apr 2010 09:46:02 +0100

BT has lost a tactical exchange in Paddington to a flood which placed the exchange underwater by at least 18 inches. The flood water caused an electrical fire.

The Paddington exchange is a critical one, not only because it is one of BT's core exchanges and connects 437 local exchanges but also 37,500 datastream circuits including the National Datastream.

The 437 local exchanges cover all the exchanges in the South from Kent to Cornwall, Suffollk, London and South Wales.

Customers will experience sync and connection but no data.

The exchange also holds the equipment for Mobile roaming in foreign countries on all the UK mobile networks.

TalkTalk kills Tiscali

nospam@example.com (John Crowhurst) — Fri, 02 Apr 2010 09:40:06 +0100

I know I'm 3 months late with this one, but when TalkTalk bought Tiscali back in January, the brand is no more. Of course, existing customers don't need to worry as their accounts remain.

Continue reading "TalkTalk kills Tiscali"

The ten most dangerous things users do online.

nospam@example.com (John Crowhurst) — Sat, 23 Jan 2010 10:05:21 +0000

Darkreading.com has a list of 10 most dangerous things users do online, they are:

Clicking on email attachments from unknown senders
Installing unauthorized applications
Turning off or disabling automated security tools
Opening HTML or plain-text messages from unknown senders
Surfing gambling, porn, or other legally-risky Websites
Giving out passwords, tokens, or smart cards
Random surfing of unknown, untrusted Websites
Attaching to an unknown, untrustworthy WiFi network
Filling out Web scripts, forms, or registration pages
Participating in chat rooms or social networking sites

Website rewrite

nospam@example.com (John Crowhurst) — Sun, 10 Jan 2010 23:23:47 +0000

I suppose it comes down to knowing your market. When I started my business back in February 2006, I didn't know what I'd need for a website, so I built something that would suffice. The first version had a login system, so people could add comments and testimonials; track trouble tickets; use live chat and be able to book jobs into the calendar. I had created a website that did everything I thought my customers would need, which turned out to be over complicated. Over a number of rewrites it became what you would have seen last week. It also became a nightmare to organise, especially since I discovered Smarty, which is what this blog uses to do templates. The current pages are developed in PHP using Smarty templates. It means all the code that makes the pages work is kept separate from the look of the pages. Templates are basically HTML pages with extra Smarty tags, so you don't need to duplicate your HTML repeatedly.

Boosting a 3G signal

nospam@example.com (John Crowhurst) — Thu, 31 Dec 2009 15:23:03 +0000

I've seen people extend a wireless network using two frying pans to create a point to point network so the signal spread is reduced and the signal is concentrated over kilometres. This is the first time I've seen 3G boosted with a metal pot.

Connectify turns Windows 7 into a wireless router

nospam@example.com (John Crowhurst) — Thu, 24 Dec 2009 15:53:11 +0000

Connectify turns Windows 7 into a wireless router (assuming the machine has a wireless card) If you have a Windows 7 laptop and you are away from home and want to connect more than just the laptop to the internet via your mobile phone, connectify works to bridge your 3G phone and the wireless built into the laptop.

Wifi network key finder

nospam@example.com (John Crowhurst) — Tue, 15 Sep 2009 22:08:26 +0100

Nirsoft wrote a program that prints out the wireless networlk keys saved on your computer, certainly useful if you have bought a laptop and can't remember what the network keys are. It will tell you your WEP and WPA keys.

Continue reading "Wifi network key finder"

LCX (Leaky CoaXial)

nospam@example.com (John Crowhurst) — Fri, 07 Aug 2009 10:26:45 +0100

In some situations, such as wifi in a hotel where multiple access points (AP) are used, rooms off the main corridor suffer from a condition called shadowing. The signal is visible across the corridor and through the doorways of the rooms but much reduced through walls.

Continue reading "LCX (Leaky CoaXial)"

Purging emails from IMAP accounts

nospam@example.com (John Crowhurst) — Sun, 14 Jun 2009 11:39:23 +0100

There are two choices that Internet providers have in providing you email. POP3 is the oldest method (called Post Office Protocol) and works by connecting and downloading emails from a mailbox. When the mail software connects, it simply asks the server to supply a list of emails, which it uses to pull down the emails with. If your software is set to delete emails when it collects them (which is the default) a delete command follows collecting the emails. POP3 is limited to one mailbox per account, and is a one way communication since it only downloads emails. IMAP is vastly different. IMAP handles many folders at a time and the user chooses to subscribe or unsubscribe to them by choice; emails are synchronised between the software and the server which makes the communication two way. IMAP also handles deletion differently to POP3. When you delete an email with POP3 its deleted; but with IMAP its only marked deleted. In the future, you may want to undelete that email (it works like the recycle bin on Windows) In Microsoft Outlook / Outlook Express / Windows Mail the deleted emails gain a line through them. In order to completely delete these emails, you must purge them by choosing Purge from the Edit menu.