asyncore and OOB data

[Douglas Wells]

In article <1184206297.813178.141000 at n2g2000hse.googlegroups.com>,
 billiejoex <gnewsg at gmail.com> writes:
> Douglas Wells wrote:
> 
> > Second, when I look at the FTP specification, I don't find the
> > concept of OOB anywhere.  So, it's not clear what OOB data would
> > mean in terms of the defined FTP commands in any case.
> 
> Steve Holde wrote:
> 
> > You are correct, however, in stating that the FTP
> > protocol doesn't support or implement out-of-band
> > data transmissions.
> 
> Wait a sec. RFC959 [1], on chapter 4.1.3 says:
> 
> [ ... ]
> 
> I believe that the TCP "urgent" flag, activated by using
> socket.MSG_OOB, should be set when client must send the "Sync" signal
> (RFC854 [2] talks about it). I think that you do not find references
> of OOB in RFC959 (FTP) just because it is specified into RFC854
> (Telnet).

The point that I was trying to make, which Steve made more clearly
that I did in the referenced paragraph, is that FTP doesn't support
OOB data transmission, not that RFP doesn't require the use of OOB
information (in the form of the Telnet Synch signal).

Note that FTP limits the commands that may be issues while a data
transfer in progress.  The RFC isn't totally explicit, but the
general notion is that issuing a data transfer command (such as
STOR or RETR) is not allowed while another data transfer is in
progress.

 - dmw

-- 
.   Douglas Wells             .  Connection Technologies      .
.   Internet:  -sp9804- -at - contek.com-                     .