Why can not call to H323 phone?

I have installed ooh322 in my asterisk and can make out going call to iax phone using netmeeting. But can not call to h323 phone from iax phone.
Following is my configuration for your analosys.

extensions.conf

exten => 50005131,1,Answer()
exten => 50005131,2,Dial(IAX2/petty|30|m)
exten => 50005131,3,Hangup()

exten => 50005134,1,Answer()
exten => 50005134,2,Dial(oh323/petty|30|m)
exten => 50005134,3,Hangucontext=incoming

oh322.conf

context=incoming
alias=petty
gwprefix=5000

context=incoming
alias=petty
gwprefix=9

context=incoming
alias=petty
gwprefix=00