FTP Timeout Troubleshooting

["Jonathan S. Abrams" <hociman () comcast net>]

Hello,

I am trying to troubleshoot an issue with connecting to an FTP server, 
and have captured some packets that match a theory I have that the issue 
is related to a timeout.  I am hoping that someone can either explain to 
me what this data means or point me in the right direction towards 
interpreting it.

When I initiated a connection to the FTP server in question, the 
following packets caught my attention.

No.     Time        Source                Destination           Protocol 
Info
23 10.212754  SERVER          ME       TCP      ftp > 49497 [ACK] 
Seq=336 Ack=33 Win=524280 Len=0 TSV=113977199 TSER=777016821

No.     Time        Source                Destination           Protocol 
Info
      24 11.057690   SERVER          ME        TCP      57314 > ident 
[SYN] Seq=0 Win=65535 Len=0 MSS=1460

No.     Time        Source                Destination           Protocol 
Info
      25 19.073737   SERVER          ME        TCP      57314 > ident 
[SYN] Seq=0 Win=65535 Len=0 MSS=1460

No.     Time        Source                Destination           Protocol 
Info
      26 35.105752   SERVER          ME        TCP      57314 > ident 
[SYN] Seq=0 Win=65535 Len=0 MSS=1460

No.     Time        Source                Destination           Protocol 
Info
      27 40.232279   SERVER         ME        FTP-DATA FTP Data: 85 bytes

No.     Time        Source                Destination           Protocol 
Info
      28 40.232321  ME        SERVER          TCP      49497 > ftp [ACK] 
Seq=33 Ack=421 Win=524280 Len=0 TSV=777017121 TSER=113977499

Here is why I think it is a timeout issue.  I am using Mac OS X, and 
when I use Transmit to connect to this server, it takes about 31 seconds 
to connect, but it does connect.  Transmit does not have a timeout 
preference that I can find, so as long as I wait patiently, it 
connects.  If I use Cyberduck, with its defaults, it will not connect.  
If I change the Cyberduck timeout preference to 31 seconds, it does 
connect.  If you look at the times on the packets above, you will see 
the first packet I pasted here has a time of 10.212754.  The next packet 
coming from ME going to the SERVER occurs at 40.232321, which is more 
than 30 seconds after the first server packet.  As such, if I don't 
adjust Cyberduck's default timeout preference to a higher value, 
Cyberduck does not connect.  This packet capture was done using 
Cyberduck, with its timeout preference set to 31 seconds, so I was able 
to connect successfully.

Ultimately what I would like to do is get the time between packet 23 and 
packet 28 to be less than 30 seconds.  This way nobody will have to 
adjust their timeout preference if they are using Cyberduck to connect 
to this server.  Does any of the packet data here suggest what I might 
be able to do to achieve that?  Any insights are appreciated.

Thanks for reading!

Jonathan S. Abrams
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