> -----Original Message----- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On > Behalf Of Arno Garrels > Sent: 31 March 2007 13:57 > To: ICS support mailing > Subject: Re: [twsocket] Questions about FTPClient > > Dan wrote: > >> -----Original Message----- > >> From: [EMAIL PROTECTED] [mailto:twsocket- > >> [EMAIL PROTECTED] On Behalf Of Arno Garrels > >> Sent: 31 March 2007 12:24 > >> To: ICS support mailing > >> Subject: Re: [twsocket] Questions about FTPClient > >> > >> Dan wrote: > >>>> So obviously those keepalive packets do not reset the timeout > >>>> (where ever it happens) however sending some bytes may help, see > >>>> above. > >>>> > >>> > >>> Try sending the NOOP command periodically whilst > >>> downloading/uploading. Most servers should support this. > >>> Not sure > >>> how the component will handle the response if it's waiting for the > >>> response from the GET/PUT though. > >> > >> You are right! > >> A response to a NOOP before GET/PUT finished would kill a transfer. > >> However some (most?) servers queue client requests, the NOOP > >> responses would the be received after the transfer completed. ICS > >> FTP server does not queue requests. > > > > In my experience, most FTP servers treat a NOOP in a special way and > > will process it and reply even during a transfer. It's worth a try. > > If they reply at once the client would treat the NOOP-response as an > response to GET/PUT, thus data socket will be closed, see procedure > TCustomFtpCli.Next2GetAsync. The FTP server of my ISP however doesn't > reply until PUT/GET completed, just tested. Instead, after the download > succeeded I was bombed with plenty of NOOP-responses. >
Yes, the client would have to be modified in case the server replies to the NOOP during the transfer. I haven't used them for a while but I believe DrFTPd, Serv-U and glftpd do this. I also remember it was a reply code that could be differentiated from the usual data transfer replies. Anyway, whether the server replies during or after the transfer, it should be sufficient to keep the connection alive as routers will see the data being transmitted. Dan -- To unsubscribe or change your settings for TWSocket mailing list please goto http://www.elists.org/mailman/listinfo/twsocket Visit our website at http://www.overbyte.be
