SFTP attempts to be more platform-independent than SCP; with SCP, for instance, the expansion of wildcards specified by the client is up to the server, whereas SFTP's design avoids this problem. While SCP is most frequently implemented on Unix platforms, SFTP servers are commonly available on most platforms. The file transfer is fast in SCP when compared to the SFTP protocol due to the back and forth nature of SFTP protocol. In SFTP, the file transfer can be easily terminated without terminating a session like other mechanisms do.