Can you share additional details about the client application?
If the client is using HTTP then the pipeline var passed to your service will not be ffdata. And you will not be able to get the filename unless the client sends it via an HTTP header.
As mentioned in our previous exchange, if there is nothing that IS is going to do with the data then converting to a string is not necessary. Have the client post the data as text/plain or as application/octet and use the bytes to back a stream you pass to EDIINT:send.
#webMethods#API-Management#soa