i updated your script

had problems with your script, so i modified it. Especially the register part was not working for me under 1.6.2 ($ character after {uri}).

Not sure why the user was cut off at 12 chars, removed that, because didnt work.

I included also checking delay because the trunk should not go under 100ms if you want to have a reliable jitter free phone connection.

http://pastebin.com/6XxU5k0w