Xlite does not Ring

I have a problem with Xlite. I have installed the latest version of Asterisk@home . I created two extensions , one for xlite and the other for an IP Telephone. I can make calls from the Xlite to the IP Phone but, when I want to make a call from my IP Phone to the Xlite it does not ring. The CLI> shows that it is calling but not ringing.

xlite Phone
[30]
username=30
type=friend
secret=12345678
record_out=Adhoc
record_in=Adhoc
qualify=no
port=5060
nat=yes
mailbox=30@device
host=dynamic
dtmfmode=rfc2833

IP Telephone
[31]
username=31
type=friend
secret=12345678
record_out=Adhoc
record_in=Adhoc
qualify=no
port=5061
nat=yes
mailbox=31@device
host=dynamic
dtmfmode=rfc2833

at the end of the CLI> When called from Xlite to the IP Phone
appears ringing
but when I call from the IP Phone to the Xlite at the end appears
called 30 but it does not appear ringing

Thank You for your help!!!