Hi Midhun,
If you are getting this message in soapui from outside your network, then that means it is hitting the pi server.
try with forming the url like
http://b2b.mycompany.com/abc?senderParty=<name of the sender party>&senderService=<name of the sender service>&interface=<name of the interface>&receiverParty=<name of the receiver party>&receiverService=<name of the receiver service>&interfaceNamespace=<name of the interface namespace>
replace the text <> with actual values from your interface