The upload protocol is carried over the HTTP (or HTTPs) protocol. Each upload request consists in a regular HTTP request directed to the following endpoint, using the POST method.
http(s)://<application-root>/UploadMgrLanding.aspx if SOAP API is used
http(s)://<application-root>/UploadMgrLandingEx.aspx if REST API is used
Content type of the form should be “multipart/form-data.”
A given upload operation is usually split into one or more upload HTTP requests, depending on the structure (e.g., multi-level folders) or size of the file/folders being uploaded.
Though not required, usage of the Chunked Transfer Coding mode for the HTTP upload requests is recommended because it enhances the overall performance of the upload operation due to the protocol design.
In the .NET framework, this chunked transfer coding can be enabled by using the HttpWebRequest.SendChunked property; while in the JDK, this feature can be enabled by using the HttpURLConnection.setChunkedStreamingMode() method.