Can't connect to my sip prov and can't think of any reason!

Hi everyone! i started with asterisk this week, went through the installation no problem, but now i want to connect to a sip provider and although i think i am doing everything ok i get the message timed out…

Here is my sip.conf, please someone tell me what’s wrong!!!

[general]
port=5060
context=incoming
register => user:pwd@iptel.org/user
registertimeout=15
registerattempts=2
srvlookup=yes
disallow=all
allow=gsm
allow=ulaw
nat=yes

[iptel.org]
type=friend
host=iptel.org
fromuser=user
fromdomain=iptel.org
secret=pwd
context=incoming
disallow=all
allow=gsm
allow=ulaw
nat=yes

Thanks! :wink: