Upload/download via gateway (central hub)

Hi

Our gateway is deployed as a central hub, and I need to upload and download files to and from our ERP system, during the gateway.

I have found following threads, but without any luck, to implement it in our system.

http://scn.sap.com/thread/3262540

http://scn.sap.com/thread/3383994

http://scn.sap.com/community/netweaver-gateway/blog/2013/08/14/how-to-upload-and-download-files-using-sap-nw-gateway.pdf

I have marked the EntityTypes as Media

And the properties looks like this:

In the class interface "ZCL_ZGW_VH_ATTACHMENT_DPC_EXT" I am using the method: /IWBEP/IF_MGW_APPL_SRV_RUNTIME~GET_STREAM where I have set a breakpoint in the first line:

  lv_entity_name = io_tech_request_context->get_entity_type_name( ).

My URL looks like this:

/sap/opu/odata/sap/ZGW_VH_ATTACHMENT_SRV/Files(Filename='test.jpg',Qmnum='123')

and the response is: Data Oobject 'Qmnum' not found

Actually I got that message for nearly every call I am doing, and aslo for this url: /sap/opu/odata/sap/ZGW_VH_ATTACHMENT_SRV/$metadata

But I don't get there?

Anyone who can guide me, so I can upload and download files?

Thanks,

Lars