Calling a Zap channel

Hi All,

I have Installed a tdm400p card installed and configure din my machine
I have an Asterisk server running in my machine. I wanted to establish a call from a SIP phone to the analog phone connected to the TDM card.

zapata.conf
context=internal
signalling=fxo_ks
channel => 1

extensions.c
[internal]
exten => 111,1,Background(hello-world)
exten => 111,2,Dial(Zap/1)
exten => 111,3,hangup()
exten => 112,1,Background(hello-world)
exten => 112,2,Dial(Zap/1)
exten => 112,3,hangup()

[joe]
type=friend
secret=welcome
qualify=yes
nat=yes
host=dynamic
canreivite=no
context=internal

I am getting a dial tone at the analoug phone so that must be working properly.
When i register the sip user i am able to call from analog phone to sip phone but i am not able to call from sip phone to analog phone. What am i missing ?? please help !!

Regards,
Arjun