On 7 Apr 2010, at 12:26, Mark Rogers wrote:
When my Linux box has a lot of connections (eg when downloading an ISO via BitTorrent), the network connectivity gets very slow for other things.
Now this could be because the total bandwidth usage is high, but I'm seeing this even when the total bandwidth on my cable connection is say 50kbps down, 10kbps up.
As this is cable, I may be hitting Virgin bandwidth limits (I'm not sure how to tell), and this may sometimes be the case because if I test with another PC on my home network I sometimes find it is also slow. Other times the other PC is fine. In any case, killing the torrent download usually (not always) speeds everything up.
So, there seem to me to be several possible issues (any/all of which may be applying at different times), but I don't know how to diagnose it. For example, it may be the total number of connections at the router (a cheap Netgear wireless cable router supplied by Virgin), or maybe even at the virgin cable modem box? I try rebooting any of these and sometimes it works, sometimes it doesn't, but I am very aware that I'm just trying random things and not really getting anywhere!
You might be hitting the bandwidth cap and hence be being throttled (see here http://allyours.virginmedia.com/html/internet/traffic.html) or there could be another possibility. I tend to find that uploading (which you tend to do a lot of with bittorrent) drastically reduces the download and upload connection speeds, so if you limit the upload speed of your torrent you may find this helps overall. There is probably a technical reason for why uploading limits the download speed too ... hopefully someone will come along and explain....