Does using MTOM on client load entire binary data in client memory before sending the soap message to server?

问题

I am struggling to understand if streaming and mtom are related or separated.

Does enabling mtom on the client mean the binary data (assuming referenced via DataHandler) will be entirely loaded into memory alongwith the soap message and then the message will be sent

or

would the soap message be sent first to the server and the server would then pull the binary data (if server does pull the data how does it know where to pull from since content id would be local to the soap message)?

来源：https://stackoverflow.com/questions/61483726/does-using-mtom-on-client-load-entire-binary-data-in-client-memory-before-sendin