Sophos and problems downloading large files

I just tested a file download and it worked for me...

(link I tested was Ubuntu: http://releases.ubuntu.com/14.04.1/ubuntu-14.04.1-desktop-amd64.iso)

Do you have an example file that fails for you that I can test?

I'm getting the same behavior as the OP while trying to download the 2012 SQL trial:

http://www.microsoft.com/en-us/download/details.aspx?id=29066

Safari consistantly stops at 212MB downloaded and then becomes unresponsive. Activity Monitor shows SophosWebIntelligence still recieving data, but eventually Safari pops up saying it was unable to finish the download. Tried opening other browsers and I was unable to get any internet connectivity at all. I disabled Sophos web protection and everything works fine.

Edit: OSX 10.10, Sophos 9.2.2. And I even tried adding microsoft.com to the 'allowed websites' but that made no difference.

Hi,

I had a chance to try this at work, on a Mac running Mavericks this time, and the same problem occurred.  I note you tried to download a rougly 1GB file:  I've found the threshold is above 4GB.  I tested this with some of the DVD Debian ISO downloads, from http://cdimage.debian.org/debian-cd/7.7.0/i386/iso-dvd/  I believe the 3.7GB file worked when I tried it, but the 4.2GB one did not.

The problem manifested slightly differently on Mavericks than on Yosemite (though the Sophos versions were a bit different - I think Mavericks was running 9.1.7).  On Mavericks, the browser continued to show the download as being in progress, but never advancing, with SophosWebIntelligence continuing to receive data, but at quite a slow rate.  On Yosemite, the browser actually gave the impression the download had completed successfully, with only the difference in file size to indicate a problem.

It only seems to be the web browsers themselves that go through SophosWebIntelligence:  I noticed, for example, Mac App Store downloads don't, and I was able to complete a 5GB download from there without problems.

Thanks very much for trying this out.

I've not seen this issue, and I'd really like to find out what's causing this problem.

How fast is your internet service?  Also, how long was it before the download was terminated by the browser?

My internet service at home has a theoretical maximum of 16Mbps - practically I get up to about 700KB/sec for downloads.  I noticed the problem in my original post after about 1.5 hours:  by that time, the browser had finished, producing a roughly 2GB file from what should have been a >4GB download.

I tried again at home again tonight.  The browser apparently stopped receiving any data after about 200MB of a 4.2GB download.  SophosWebIntelligence continued to download data at roughly the capacity of my broadband.  However, while it received data, it stopped sending any (i believe it's meant to send on the data it receives "internally" to whatever application is really the consumer of the data).

After telling the browser to cancel the download, the above behaviour continued for some minutes (over 4), during which time I had could hardly access the web.  Things did recover after some time, and web browsing started working.

I did not let the download run for as long as my original attempt.  I wonder if the download would eventually have terminated, as it did the first time.

Slighlty related to this issue but needs more investigation at my end. I've been having issues for the last 6 months or so downloading iTunes apps with larger ones frequently stopping with a generic error. Sometimes it takes 3 or 4 attempts to download the file. Since running the public beta of Yosemite and the full release, I've had issues with slow download speeds. There's a few discussions on various Apple boards about this issue. 

My download speeds on speedtest.net had dropped from 160 MBs to 50-70 maximum in both Safari and Chrome on my Mac mini. If I rebooted it into Windows 8.1, then I got the full speed. This didn't happen in Mavericks, just Yosemite.

I found a link today that suggested that disabling Web Protection in Sophos sped up the internet connection so I tried it and the speed resumed back to 160 MBs but dropped again when I reneable the Web Protection. A 100 MBs difference is quite significant.

The reason I'm mentioning it here is I was able to download all the updates to my apps via iTunes for the first time in ages, no stalls so I'm wondering if both issues are related to Sophos. 

I'm running Sophos 9.2.2