Synchronizing file data between computer systems

Non-limiting examples of the present disclosure describe implementation of an exemplary synchronization protocol to identify file data for synchronization as well as negotiate how to achieve data transport for synchronization of the file data. In one example, a request for synchronization of data is received from a processing device. In response to receiving the request, a response is generated. The response may comprise: identification of file data for synchronization, instructions for accessing the file data and instructions indicating a data transport protocol to utilize to obtain the file data. The response may be transmitted to the processing device, for example, to enable the processing device to synchronize file data. Other examples are also described.