October 2010 Archives

Here are a few notes about BT ISDN 2e (BRI) lines that when I was first learning about phone systems configuration could really have done with being laid out. I hope it helps somebody in the UK (I’m assuming that this kit isn’t available in its exact form elsewhere).

• There are two types of ISDN line offered by BT: BRI and PRI (ISDN 30).
• BT’s ISDN 2e is BRI
• This is the same standard known as EuroISDN
• Each box on the wall supports two channels (lines)
• There are two RJ-45 connectors in the bottom of the present units. These exist so that you can plug two handsets directly into the box. (These are not standard PSTN handsets. The jacks are different - don’t try and force them!)
• Each RJ45 socket carries both lines i.e. you only need to plug in one of them for a PBX
• The type of cable required to fix in here is a standard Cat5 cable (or above).

Just a shot note as this is something that I’ve been asked about recently. Hopefully the distinction I make below will help a beginner somewhere!

To restart apache from the command line, the command is (typically):

sudo /etc/init.d/apache2 restart

There are some errors that you may get whilst running various commands. Below are a list of commands, associated errors and their explanations;

/etc/init.d/apache2 restart
You may get an error for not using ‘sudo’

sudo /etc/init.d/apache2 restart
Not in sudoers file
Your user must have appropriate sudo priveledges

apache2 restart
or sudo apache2 restart
Usage: apache2 [-D name] [-d directory] [-f file]
[-C “directive”] [-c “directive”]
…etc…
Typically this error will occur if you have navigated to the /etc/init.d directory. *This will not work!*

apache2 -k restart
apache2: bad user name ${APACHERUNUSER}
You don’t need to put the -k in. Also see above if you are trying this having navigated to the /etc/init.d directory

Today I found a Facebook privacy vulnerability affecting dates of birth. The scenario:

• The Facebook user hides their date of birth from view
• When today’s birthdays are viewed, those who choose to publish their year of birth have their age displayed. Those who have opted to hide their year of birth in their privacy settings do not have their age published. ( http://www.facebook.com/?sk=bd )

However…

• When viewed via the Facebook mobile site, their age is published ( http://m.facebook.com/birthdays.php )

Obviously from this, the individual’s date of birth can be easily calculated.

UPDATE: I have of course notified Facebook of this privacy flaw.