OData v4 - Media Handling

Hello,

I am currently working with OData v4, which is connected to an external (non-Fiori) application.

Current request is to prepare service, which will be called by that application, via method POST.
With use of this method, external application need to send XML file to SAP.

I have prepared new service, with use of structure, which contains fields:

• File Name
  
• Mime Type
  
• Data (XSTRINGVAL)

Unfortunately, during test in /IWFND/GW_CLIENT, I am receiving below error:
"The server is refusing to process the request because the entity has an unsupported format"

First question, is it possible to transfer file to SAP, with use of OData v4, in my system?

System specification:

SAP ERP 6.0 with EHP8
SAP_BASIS 750 0016
SAP_ABA 750 0016
SAP_GWFND 750 0019

Second question, has anyone came across simmilar problem and know how this can be solved?

I know, that in OData v2, in order to process files (streams), model definition must be modified and properties Content Type and Content Source set, but in definition for OData v4, I cannot see such properties.

Best regards,

Damian Dworak