Asterisk and Skype Connect Issue “Can't Register”

I am trying to connect skype manager with AsteriskNow, the problem is i can’t seem to register the SIP… I tried every thing possible but still no success…

$ asterisk -rx “sip show registry”

$ asterisk -r

and here is my configuration for the trunk:

type=friend
username=9905XXXXXXXXX
fromdomain=sip.skype.com
fromuser=9905XXXXXXXXX
realm=sip.skype.com
host=sip.skype.com
dtmfmode=rfc2833
secret=XXXXXXXXXXXX
nat=no
insecure=invite
qualify=yes
disallow=all
allow=alaw&ulaw
amaflags=default
trustrpid=no
sendrpid=yes
context=from-trunk

Register String:

9905XXXXXXXXX:XXXXXXXXXXXXX@sip.skype.com/9905XXXXXXXXX

i also tried to add the registration string to sip_additional.conf

i can telnet from a different machine in the same network to sip.skype.com 5060, so my ISP isn’t blocking the 5060 port… but actually i am unable to telnet 5060 from the Asterisk even that my firewall should be off…

netstat -ntulp, didn’t show the port 5060

nmap -v -sV localhost -p 5060, returned: 5060/tcp closed sip

is my problem with the port? and if so how can i enable it, or what seems to be my problem…?