I'm fairly new to Asterisk, but I wanted to try 1.6 to see if I could get it working with MS Exchange 2007 UM. On a clean install, I found that there was no SIP functionality - I couldn't even run SIP commands from the cli. Looking through the log file, there were lots of error messages about missing #include files - for example most of the files listed in sip.conf did not exist.
Once I created these files, sip functionality was restored and I could register phones OK - I'm still trying to get it talking to Exchange though.
Once I created these files, sip functionality was restored and I could register phones OK - I'm still trying to get it talking to Exchange though.


but any progress on FAX???

My thoughts are this is a fairly complex process which is prone to breakdowns and if it breaks down it takes your phone system with it. 
I didnt mean to.