EDI - B2B or A2A??

Hello guys.

I have a conceptual question regarding the configuration of a business scenario with an outside partner using EDI.

As general ones would say that because the partner is outside the LAN its a B2B scenario ,but what if the EDI box sits inside my LAN...what then?

does XI adds additional elements to the XML structure(except for security and agreements) when we configure the service with party for a b2b scenario at configuration time??

Appriciate your opinion...

Regards.

Nimrod