Phases

Phases to transfer a file

** [ Source ]    &   [Destination]    [Phase]
**
**    CWD        &   CWD [ MKD [ CWD ] ]  1 | Go to dir, create if needed.     [1]
**  CCSN/SSCN    &    [CCSN/SSCN]         2 | SSL, send to one of them.        [2]
**   [PROT]      &      [PROT]            3 | SSL, go privacy, or not.
**    TYPE       &       TYPE             4 | Set Binary, if needed.
**               &       SIZE             5 | Exists? Size? Resume? Res-Last?  
**   [PRET]      &      [PRET]            6 | If pre-transfer
**   [PASV]      &      [PASV]            7 | Send pasv to one site
**   [PORT]      &      [PORT]            8 | Send port to the other.
**   [REST]      &      [REST]            9 | If resume, send restart point    [3]
**               &       STOR            10 | Attempt stor
**               &      [XDUPE]          10 | Look for XDUPE messages in failures
**   [RETR]      &                       11 | Attempt retr
**               &      [XDUPE]          11 | Look for XDUPE messages in 226
**    NOOP       &       NOOP            12 | Stop idle out until we are rdy   [4]

• [1] This means that creation of destination directories only occur once we try to transfer a valid file. If there are no files to transfer, the destination directory is not made. (However, if dskipempty is set to NO we should create it. Currently not implemented)
• [2] Is ignored if data_TLS, or optional FXP_TLS, is set to YNA_NO.
• [3] The REST command need to be very close to the transfer commands as some commands will clear the REST value if executed.
• [4] Waiting for 150 messages, and also 226 is also considered a phase.