Sceptic: Can't help with the first question, im sure they do it differently to OZ.
But I can help with your second question.
You would need to purchase an ATA & set it up as an extension in the phone system, but it is extremely unreliable, especially if you are sending the call over VoIP. You could look for one that supports the T38 faxing protocol & find a VoIP company that does also, but you're still probably not going to like the results.
For just receiving, Asterisk can receive faxes & email them to you as a PDF, you will find the configuration In Phones Setup under General Settings
Regards,
Josh