281600 - upload bugs (http post) are tcp problems ?

Status: RESOLVED WORKSFORME

(Firefox :: General, defect)

Description

[simon]

User-Agent:       Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.5) Gecko/20041107 Firefox/1.0
Build Identifier: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.5) Gecko/20041107 Firefox/1.0

I have massive problems using FireFox to upload pictures via http post to
different webservers. Very often the upload stalls after some kilobytes.

I sniffed the network traffic with ethereal to see what is exactly happening. If
you inspect the packet flow while the upload stalls you will almost see the same
happening:

- The server sends multiple (>50) duplicate TCP ACK packets
:loop
- wait 10
- The client is retransmitting
- wait 10 seconds
- The client is retransmitting
- wait 20 seconds
- The client is retransmitting
- wait 40 seconds
- The client is retransmitting
- wait 40 seconds
- The client is retransmitting
- wait 20 seconds
- The server sends a FIN to close the connection 
- goto loop

Hint: To find the interesting packets add this ethereal filter: "tcp.analysis.flags"

The problem only occurs on my internet connection (128kbit upstream via a DLINK
router). I couldnt reproduce it on my webserver in my lan.

Here is the interesting part. If i upload data via ftp or ssh it sometimes
stalls too. But it stalls for very short time only. Normally the server sends 2
duplicate ACK packets and almost immediately the upload resumes with full speed.
Where is the difference to FF?

Is FF using some kind of "special" TCP sockets ?

Reproducible: Sometimes

Steps to Reproduce:
1. upload a file via http post

Actual Results:  
transmission stalls

Expected Results:  
transmission should complete

Comment 1

[Ben Fowler]

It is not may call, but if it is your opinion that there is a defect
in Firefox (last time I saw a tcpdump matching your description was
last century when some of an ISP's modems wouldn't converse with the
linux 2.0.x tcp stack) then you should attack a simultaneous tcpdump
and http log http://www.mozilla.org/projects/netlib/triaging.html .

I doubt it helps, but your description seems to show both
Firefox and your tcp stack working, maybe there are some packet options
being set that are not helping you ...

Comment 2

[simon]

Bingo, the DLINK DI-714P+ DSL Router seems to have problems with http traffic.
After a firmware upgrade it works for me.

There are some other bugs open related to http upload problems, perhaps someone
should ask, if they use DLINK products...

Fails to upload http:
Current Firmware Version: 1.23
Firmware Date: Mon, Jun 30 2003

Works for me:
Current Firmware Version: V1.33
Firmware Date: Thu, Jun 17 2004

Comment 3

[simon]

wfm
If other people complain about such problems, ask if they use DLINK products...