Huge data volume

Hi All,

My scenario Portal-PI-ECC.

A huge volume data (6-8 GB) need to be transferred between Portal to ECC(Asynchronous).Could anyone suggest me on which method is the best to go .

Portal=WSDL or JAVA Proxies?

ECC=RFC/ABAP Proxies?

Thanks in Advance.

Regards,

Lavanya.B