Does avast increase download volume?

[gauthier]

Hello,
I have Avast home 4.7.492 On XP(family)
My internet provider allows me to download up to 10G per month. It is enough for me.
But, I reach this limit too fast and my provider charges me for each more GB
After investigations on my consumption I noticed that avast multiplies my download between 2 to 3 times
I made some tests with internet explorer and activating/deactivating resident protection. I use "netstat -e" to  know number of bytes downloaded
the example below is for the www.avast.com home page

avast activated : 809279 bytes
avast shut down : 372950 bytes

To prevent distortions with the cache of IE, I made the operation multiple times and have approximatively same figures.

Is it a normal feature of Avast or a configuration problem?

Thanks a lot,
Gauthier

[DavidR]

I would say it is a configuration issue, but how to overcome it is the question. The problem is how does your ISP determine the download figure, is it at ISP or is there some monitoring program on your system ?

The avast web shield intercepts http traffic into its localhost (127.0.0.1) proxy so that it can scan content before it arrives ultimately at your browser cache so the monitoring process may be double counting.

Do you have to use a proxy to connect to your ISP (possibly to monitor your bandwidth) ?

[oldman]

DavidR is on the right track. There was a post quiet awile ago about the same issue. The counting software was reading the data going through web shield and, darn I can't remember what else was being counted. But most ISP have a feature on their web site, within your account, to see what  your usage is. You can try to see what they have recorded for your usage and compare.

Maybe someone else can remeber the post and how they got around it.

[DavidR]

I did a quick search for the other topic on double counting but didn't find it.

I have done a more detailed search and found this, http://forum.avast.com/index.php?topic=22003.0, I haven't checked it completely

[oldman]

@DavidR

Yes that's one of the threads I recall, but it seems there was another with more detail. However, since reading the post in your link, I'm sure the solution was to ignore local traffic.

[DavidR]

Yes I too think the solution was to exclude local traffic, but I'm unsure if there was anything in K9 using a proxy and having that scan first followed by web shield's local proxy. e.g. set the browser to use the K9 proxy and add the K9 proxy to the wen shield redirected http ports.

I'm also don't know how much difference there is in what K9 does and what web shield does to disable one of them if they basically do the same thing.

[gauthier]

Thanks for these quick answers, even if I don't understand everything...
The counter my provider uses is only on his side. There is no counter on my side.
There is a web interface where I can check my usage, but this interface is refreshed with a delay of some days.
I now have the stats of the 13th of April, when I started to record my consumption. I recorded 470 MB, but my provider has recorded only 278MB. I'll continue for some days to be more accurate, but it appears that using "netstat " is probably not the good way to record internet usage. Moreover, I'm not sure anymore that Avast is responsible of my high consumption.

[oldman]

Thanks for these quick answers, even if I don't understand everything...

Feel free to ask for clarification.

The counter my provider uses is only on his side. There is no counter on my side.
There is a web interface where I can check my usage, but this interface is refreshed with a delay of some days.
I now have the stats of the 13th of April, when I started to record my consumption. I recorded 470 MB, but my provider has recorded only 278MB.

So the official counter is on the sever side? Well that's a good thing.

I'll continue for some days to be more accurate, but it appears that using "netstat " is probably not the good way to record internet usage.

I was thinking perhaps, netstat is reading traffic between the server and web shield and web shield and your browser. You could try a secure (https) site, there will only be traffic between your browser and the server.

Moreover, I'm not sure anymore that Avast is responsible of my high consumption.

If you do find another cause, please post it here. It may help others.

Welcome to the forums.

[DavidR]

Thanks for these quick answers, even if I don't understand everything...
The counter my provider uses is only on his side. There is no counter on my side.
<snip>
I now have the stats of the 13th of April, when I started to record my consumption. I recorded 470 MB, but my provider has recorded only 278MB.

I'll continue for some days to be more accurate, but it appears that using "netstat " is probably not the good way to record internet usage. Moreover, I'm not sure anymore that Avast is responsible of my high consumption.

Speed of response on the avast forums is the norm and not the exception, unlike many other support forums

It appears from your figures that your provider is correct in only recording true download traffic. That will be confirmed over the longer period you monitor it.

I think netstat is most likely the issue as that would record all network traffic local and remote (internet) connections into the web shield proxy then to your browser cache and possibly also include the listening ports for the Internet Mail scanner, so it would be double counting the email traffic into the internet mail proxy and from that into your inbox, etc.

I too doubt there is any increased traffic as a result of avast.

Welcome to the forums.