...
SOAtest supports flowed transactions via the WS-Atomic Transactions protocol and MS OLE Transactions protocol for WCF web services. For more information, see .NET WCF Flowed Transactions.
Streaming Large Request Messages
To enable streaming of requests with large binary data, the SOAP Client must have MTOM enabled as described in Sending MTOM and XOP Messages. An intermediate MTOM representation is necessary to stream the message to the .NET Binary XML encoder.
Configuring Global .NET System Properties in SOAtest
...