Cant download via FTP during offpeak

Connection issues, drop outs or speed related faults for ADSL and ADSL2+ services
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dtn22
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Joined: Tue Jul 14, 2009 2:55 pm

Cant download via FTP during offpeak

Post by dtn22 » Sat Apr 24, 2010 12:58 pm

Recently i cant download anything via FTP during offpeak. It download for few minutes and time out and i get disconnected. During peak download is ok, nothing wrong. I have submitted a job with exetel for 3 weeks now and they still cant fix it yet. exetel asked me to download from ftp://ftp.optus.net.au/pub/ for testing but its still the same, got time out less then 2 mins of download. Does anyone has the same problem? look like ftp is block during offpeak.

Dazzled
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Re: Cant download via FTP during offpeak

Post by Dazzled » Sat Apr 24, 2010 3:56 pm

It doesn't affect me in the morning, say 6am - noon. Are you having the trouble only with a particular site or ftp client? Can you pipe the exchange to a terminal or file to see if anything pops out?

It may turn out to be a firewall issue, blocking part of the conversation, such as ls or get. Can something like curl transfer the files?

dtn22
Posts: 91
Joined: Tue Jul 14, 2009 2:55 pm

Re: Cant download via FTP during offpeak

Post by dtn22 » Sun Apr 25, 2010 7:54 am

apply to all ftp, i even shut down my firewall and still cant download, doesnt work on my ps3 as well, normally i can download update on my ps3 but it just time out. How do i do this according to your instruction? "Can you pipe the exchange to a terminal or file to see if anything pops out?"

Dazzled
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Re: Cant download via FTP during offpeak

Post by Dazzled » Sun Apr 25, 2010 8:10 am

I'm off now for much of the day, but some FTP clients can show or even save the various parts of the FTP "conversation". If yours can't, as a last resort there are the CLI commands in a terminal/DOS box -
Windows: http://www.microsoft.com/resources/docu ... x?mfr=true
Linux: http://linux.about.com/od/commands/l/blcmdl1_ftp.htm
You'll need the ftp protocol commands to actually download a file. This information will show where in the process the problem actually occurs. I mentioned checking firewalls blocking requests because it's a known Windows problem.

Dazzled
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Re: Cant download via FTP during offpeak

Post by Dazzled » Sun Apr 25, 2010 5:59 pm

To show what I meant about pinning down where the problem shows up, here is an ftp download (names changed) of a tiny file from an Exetel free site, done using the terminal CLI. The terminal prints the messages received from the server. Many GUIs have a section that shows this exchange.

Code: Select all

$ftp home.exetel.com.au
Connected to home.exetel.com.au.
220 220.233.0.59 FTP server ready
Name (home.exetel.com.au:XXX): fw_XXX
331 Password required for fw_XXX
Password:
230 User fw_XXX logged in
Remote system type is UNIX.
Using binary mode to transfer files.
ftp> cd doc
250 CWD command successful
ftp> ls
200 PORT command successful
150 Opening ASCII mode data connection for file list
drwx---r-x   2 fw_XXX   users        4096 Apr 18 09:27 .
drwx---r-x   3 fw_XXX   users        4096 Mar 17 09:22 ..
-rwx---r-x   1 fw_XXX   users          17 Dec 15  2008 WWW.txt
-rw-r--r--   1 fw_XXX   users      940924 Apr 18 09:27 QQQ.txt
-rw-r--r--   1 fw_XXX   users      448495 Apr 18 09:26 YYY.pdf
-rwxr--r-x   1 fw_XXX   users    51048797 Apr  8 10:15 ZZZ.pdf
226 Transfer complete
ftp> get WWW.txt
local: WWW.txt remote: WWW.txt
200 PORT command successful
150 Opening BINARY mode data connection for WWW.txt (17 bytes)
226 Transfer complete
17 bytes received in 0.01 secs (2.1 kB/s)
ftp>

dtn22
Posts: 91
Joined: Tue Jul 14, 2009 2:55 pm

Re: Cant download via FTP during offpeak

Post by dtn22 » Wed May 05, 2010 8:35 am

An update to my problem.

I now 100% sure that there is nothing wrong with my setup both hardware/software. As last night i successfully download a 100Mb file from a ftp site during peak usage. Just to make sure its not a fluke, i managed to downlod it twice with no problem. The same site was test for download this morning with the same file during offpeak and like before it timeout and disconnect the session. I tried a few times with no success. I refuse to believe Exetel does not block or throttle my connection as how do you explain what happened between peak and offpeak? If it work during peak it will also work during off peak unless there is a different set up between the 2.

Dazzled
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Re: Cant download via FTP during offpeak

Post by Dazzled » Wed May 05, 2010 9:16 am

I don't think Exetel is deliberately spoiling anything. Are you behind a firewall? Are you using Passive mode PASV? Which server is it timing out? Does your client app periodically keep the session alive? What's happening with the PORT command? And lastly, because of the time of day factor, is high latency interfering with any part of the conversation as presently configured?

FTP is a complex protocol from much earlier times in computing history (1970s), and has to be configured correctly at both ends. Windows firewalls & client apps, as well as domestic NAT routers, sometimes have problems.

dtn22
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Joined: Tue Jul 14, 2009 2:55 pm

Re: Cant download via FTP during offpeak

Post by dtn22 » Wed May 05, 2010 10:23 am

Hi Dazzled,

i have tested with the same setting(with fire wall and no fire wall) for both peak and off peak. Again i can download a 100Mb during peak but unable to download the same file during offpeak. This is not just on one occasion, i tested on a different day as well and yet i can download during peak and not off peak. Im using the same computer the same setup ,same ftp site and same file to download. There is obviously some settings is not the same between peak and off peak and i'm sure its not at my end. I havent test the port cmd test as you suggested, as the problem is purely not at my end. If i cant download during peak then there is a different story.

Dazzled
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Re: Cant download via FTP during offpeak

Post by Dazzled » Wed May 05, 2010 11:14 am

I believe you that it is failing during off peak only. It shouldn't. Do you have an extremely high off-peak latency problem? Is it only one server? Otherwise I cannot see why it's not fixable at your end. FTP is notoriously fussy and Windows/NAT troubles and solutions are widely reported.

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