WRT110 router - FTP upload problem - Timeouts on large files
|Reported by:||ftpeter||Owned by:|
|Keywords:||router, upload, large, files, timeout, send, noop||Cc:|
|Component version:||Operating system type:||Windows|
|Operating system version:||WinXP Home, Win7 Ulti|
WRT110 router - FileZilla Client, FTP upload problem
- Timeouts on large files - ==
When I upload files via FTP and if the transfer of a file takes more then 3 minutes,
then my FTP programs doesn't jump to the next file to be uploaded when the previous one has just been finished.
The problem occurs only if I connect to the internet behind my wrt110 router.
I have tried FileZilla, FTPRush and FlashFXP
FTP softwares to upload via FTP.
At FileZilla sending keep-alives doesn't help,
BUT FTP upload properly works at FlashFXP if I send noop during transfer:
Sending anti-idle keep alives also does not work at FlashFXP from behind wrt110 router.
At FileZilla I can right-click->Refresh the FTP window during transfer,
but I can't do that at FlashFXP.
This might be connected with the problem I have written above, I don't know.
Please if you can, put similar solution into FileZilla as it is in FlashFXP.
This is exactly what I am experiencing --> On FileZilla's site I can read this:
http://wiki.filezilla-project.org/Network_Configuration#Timeouts_on_large_files '''Timeouts on large files''' If you can transfer small files without any issues, but transfers of larger files end with a timeout, a broken router and/or firewall exists between the client and the server and is causing a problem. As mentioned above, FTP uses two TCP connections: a control connection to submit commands and receive replies, and a data connection for actual file transfers. It is the nature of FTP that during a transfer the control connection stays completely idle. The TCP specifications do not set a limit on the amount of time a connection can stay idle. Unless explicitly closed, a connection is assumed to remain alive indefinitely. However, many routers and firewalls automatically close idle connections after a certain period of time. Worse, they often don't notify the user, but just silently drop the connection. For FTP, this means that during a long transfer the control connection can get dropped because it is detected as idle, but neither client nor server are notified. So when all data has been transferred, the server assumes the control connection is alive and it sends the transfer confirmation reply. Likewise, the client thinks the control connection is alive and it waits for the reply from the server. But since the control connection got dropped without notification, the reply never arrives and eventually the connection will timeout. In an attempt to solve this problem, the TCP specifications include a way to send keep-alive packets on otherwise idle TCP connections, to tell all involved parties that the connection is still alive and needed. However, the TCP specifications also make it very clear that these keep-alive packets should not be sent more often than once every two hours. Therefore, with added tolerance for network latency, connections can stay idle for up to 2 hours and 4 minutes. However, many routers and firewalls drop connections that have been idle for less than 2 hours and 4 minutes. This violates the TCP specifications (RFC 5382 makes this especially clear). In other words, all routers and firewalls that are dropping idle connections too early cannot be used for long FTP transfers. Unfortunately manufacturers of consumer-grade router and firewall vendors do not care about specifications ... all they care about is getting your money (and only deliver barely working lowest quality junk). To solve this problem, you need to uninstall affected firewalls and replace faulty routers with better-quality ones.
Change History (14)
comment:8 by , 8 years ago
|Summary:||WRT110 router - FTP upload problem - Timeouts on large files → WRT110 router - FTP upload problem -|
follow-up: 12 comment:9 by , 8 years ago
|Summary:||WRT110 router - FTP upload problem - → connection unavailable|
comment:11 by , 8 years ago
|Priority:||critical → normal|
|Summary:||connection unavailable → WRT110 router - FTP upload problem - Timeouts on large files|