Integration between SAP ERP and SAP PO single stack in different Network / Landscape

Hi All

My requirement is as below:

ECC (Network abc)  -->  SAP PO (Network xyz) single stack.

Now I need to send proxy data from ECC to SAP PO and both are in different network altogether.

I know I can create Outbound Service Interface in PO and can take out WSDL and then using this WSDL ABAPer can generate proxy in ECC using TCODE SE80.

Now lets say proxy is generated. Rest what all settings I need to do so that data can flow from ECC to SAP PO?

Regards,

Dheeraj Kumar