Simultaneous Connection Problem??

greg_SA

greg_SA

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Hi,

Over the last 2-3 months, my internet connection (using 6110 as a modem) stalls after a while - I get no data on the downlink.

It seems to happen when I open lots of windows (tabs) in firefox at the same time. I also get the same problem when downloading via freedownload manager using multiple connections (downloading a file i say 5 parts at the same time). If I just save the file in firefox, it downloads fine!

Does vodacom restrict the number of simultaneous connections?

Everything used to work fine for the last 2 years - its only a problem lately.

Any ideas? I have tried another phone, and another PC, but get the same problem.

Thanks,
Regards,
Greg
 
greg_SA said:
Hi,

Over the last 2-3 months, my internet connection (using 6110 as a modem) stalls after a while - I get no data on the downlink.

It seems to happen when I open lots of windows (tabs) in firefox at the same time. I also get the same problem when downloading via freedownload manager using multiple connections (downloading a file i say 5 parts at the same time). If I just save the file in firefox, it downloads fine!

Does vodacom restrict the number of simultaneous connections?

Everything used to work fine for the last 2 years - its only a problem lately.

Any ideas? I have tried another phone, and another PC, but get the same problem.

Thanks,
Regards,
Greg
Click to expand...

No, I often have closer to 20 active windows open. Do you get the same result with IE?

Around when do you think it started?
 
About 2 months ago - beginning of March I think.

Got the same results on a different PC running IE (laptop).
 
Well, the problem still persists.

I'm going to try MTN...
 
Last edited:
Maybe check the number of half-open connections your PC currently has - I originally set mine to 100 (opposed to Windows default of 10) - after an MS update around Feb/March, mine were set back to 10 - the usual MS intrusion... :p

I set them back and all was fine...

Half-open limit fix is a program designed to change the maximum number of concurrent half-open outbound TCP connections (connection attempts) in the Windows system file tcpip.sys.

Microsoft first introduced this limit in Windows XP SP2 (Service Pack 2) and is present in later versions of Windows. This was done to try to slow the spreading of viruses and malware from system to system and also to reduce the impact of infected systems participating in DoS (Denial of Service) attacks.

This limit makes it impossible for Windows systems to have more than 10 concurrent half-open outbound connections. After 10, new connection attempts are put in a queue and forced to wait.

Therefore, the speed of connection to other computers is actually limited.

P2P (peer-to-peer) programs (µTorrent, BitComet, eMule, P2P TV etc.) are generally the most affected programs. As they use up all 10 of the half-open connections, other Internet activity, especially the loading of web pages, can be extremely slow. The delay before the beginning of opening can make some tens seconds. This happens regardless of the speed of your Internet connection.

Half-open limit fix takes care of this problem by increasing the maximum limit of half-open connections. For the overwhelming majority of Internet users, changing the limit to 100 will be more than sufficient.
Click to expand...
 
This is very interesting. And exactly the kind of hidden stuff that often affects us without us realising it.

Can anyone confirm an improvement after changing this value?

Also, do we know if this can't directly be changed in the registry by hand rather than running a program to do it. "Registry fixers" always make me nervous. :)


/added

Read up more on this and Howard is spot-on, I believe. Read this link as well for a check and fix on XP.

And this one for Vista.
 
Last edited:
davemc said:
It's not so simple, the tcpip.sys file needs to be changed. See http://www.lvllord.de/
Click to expand...

Yeah, saw that. Especially for Vista.

Have updated the post above with more details.

Not saying this is indeed Greg's problem (though it does seem to fit the symptoms), but it's a very good example on how one needs to consider the complete end-to-end connection as a single system.
 
Just ran the patch, and I thought it worked... then shortly afterwards, my connection stalled again - not data on the downlink. Even if I close and re-open Firefox or IE, the connection stays stalled (no data received) :(

I just got an MTN sim card and connected with it - I get the same problem!

Do MTN and Vodacom share any resources (towers, etc?)

Strange thing is that I get the same problem on my girlfriends laptop.

Maybe I should update the firmware on my phone (Nokia 6110 Navigator)? I have tried 2 different phones as the modem, both 6110s though. I just don't understand that everything was fine for the previous 1.5 years :(
 
I'm battling to simulate the problem.

On both XP-SP2 and XP-SP3, I've got much more than 10 concurrent sessions open and are not seeing the event appearing in the syslog.

Hmmm....wonder if I'm actually using TCP and not UDP?

I'm streaming from youtube, another webcam site (using microsoft media player) and doing downloads from a news server using telnet. Each about 10 concurrent sessions.

So, if they're all TCP, I should see the event. But I'm not.


/added

OK, both Telnet and Flash use TCP. This implies I'm running much more than 10 concurrent TCP sessions (as confirmed by netstat) and a bunch more in a waiting state.

So why am I not seeing the error appear?

It seems the limit is only imposed on concurrent attempts opening new TCP connections, i.e. if you open up one tab after the other, you won't see this. But if you try to open up multiple tabs at the same time (FF restoring previous sessions, for example) or you have a P2P program starting up, you'll probably see this.
 
Last edited:
Hmmm... I was just browsing this forum - I was reading 4 threads (4 tabs open in firefox), and the connection also stalled - tried closing firefox, tried IE, no luck - had to reconnect.

So it doesn't seem to be related to the number of active connections, though the connection stalls much quicker that way.
 
greg_SA said:
Hmmm... I was just browsing this forum - I was reading 4 threads (4 tabs open in firefox), and the connection also stalled - tried closing firefox, tried IE, no luck - had to reconnect.

So it doesn't seem to be related to the number of active connections, though the connection stalls much quicker that way.
Click to expand...

Do you use any type of P2P program?
 
greg_SA said:
The was no P2P software active at the time - I don't run it by default. Free DL Manager was open in the background, but not actively downloading anything.
Click to expand...

Do a netstat on the command line and see how TCP sessions you have.

Try and reduce them as much as possible and check if i makes a difference.

Do you see the TCP event in the event viewer?
 
Greg_SA...

Do this for me pls.
Use Ginggs' app instead of VMC or w/e.
Soon as the connection stalls, switch the profile to "GPRS/EDGE Only".

Continue browsing possible now?
Switch it back to "3G/HSDPA Only" after about 2 minutes.
Continue Browsing possible now?
 
vodacom3g said:
Do a netstat on the command line and see how TCP sessions you have.

Try and reduce them as much as possible and check if i makes a difference.

Do you see the TCP event in the event viewer?
Click to expand...

I have about 13 TCP entries and about 11 UDP entries...

All the UDP entries say *:*

I had netstat setup with netstat -a 3 so that it updates all the time - when the connection stalled, the TCP list was shown, but no UDP?

Dunno if that means anything.

The least I can get my TCP list to is 8 entries.

Should I post the list?
 
wheunis said:
Greg_SA...

Do this for me pls.
Use Ginggs' app instead of VMC or w/e.
Soon as the connection stalls, switch the profile to "GPRS/EDGE Only".

Continue browsing possible now?
Switch it back to "3G/HSDPA Only" after about 2 minutes.
Continue Browsing possible now?
Click to expand...

I am using my phone to connect to the internet - are the apps you are talking about for the USB modem?
 
While browsing the forum now (2 threads), my netstat shows 25 TCP connections (most are TIME WAIT) ?
 
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