Handle Attachement in SAP PI

Hi all,

I have the snenario described bellow :

I have To handle attachments in SAP PI using Webservice ( SOAP protocole) .So In my ESR I Have mapped my two fields fiald1 and field2, and in The sender I choose 'Keep attachement', then I generated the WSDL to give it to the portal team.

My question, is this enought ( Choosing keep attachement), to handle attachement in SAP PI ( How the attachment will be encapsulated in SOAP protocole ) , or I have missed something else ?

Regards