Blessed day everyone

This is my 1st time to work with a Web Service, please bear with my doubts.

My requirement is to send SAP data to 3rd party system (.net app) during PGI via Web Service.

1. Can we transmit data (from SAP directly to the 3rd-party) without any integration server (only Web Service)?

2. Is the Web Service acts as the middleware?

3. Also, please correct what's missing in my steps:

- I've created RFC FM

- Created the Service Definition in SOAMANAGER (WSDL file generated)

- Created the Logical Port

- Created the Proxy (Service Consumer)

- Include the proxy program in my RFC FM --> When I test, I am getting "GET_BUSINESS_SYSTEM_ERROR" after calling the proxy method (system generated)...

Searching this error, gives me explanation about XI or PI server...

Can someone help me to have clarity with my confusions?

Appreciate any response. Thank you!

-AKO