I'm trying to develop a simple application that let communicate two computers in a LAN for transferring files. My idea is that: using dbus/zeroconf each machine can see other's service and can connect with it (I need something without authentication or so) having a lan with 2 machines A asks B if he can send a file if B accepts, begin transferring if B refuse, send an error back It would be nice to transfer big files (not loaded all in memory) and the ability to stop/resume the upload/download and the integrity check. Is there a protocol that let me do this stuff or is better to implement a protocol on my own? (I'd like that the system is flexible to further extend for example, implement shared folders and so on) In the latter case it's convenient to use one port or two ports like ftp does?