Two clients with big impact on the network

[vrapp]

I noticed that some applications literally bring the home network (RT-AC68R, and RT-N66U before that; firmware throughout many builds) on the knees. In my home I have more than 15 devices, and it's not unusual that one family member is watching youtube on desktop computer, while another is watching netflix on the wifi-enabled DVD player, yet another is talking on OBI phone, bandwidth consumption in Traffic Monitor is close to the limit (6M/768K) and with all that it's not a problem for others to browse internet. But if I launch update of WorldOfTanks, which occurs using its own torrent client, or iPhone 5 or 6 is updating its apps, everybody's browsing slows down many times, and browser sits on "resolving" or "connecting" for 5-10 seconds and often times out. No changes in QoS have any effect. Remarkably, bandwidth utilization is not even close to the limit, it's at 40-50%, but as long as the consumer of those 40-50% is one of these two clients, it becomes slow.

Does anybody have any insight, what is going on, why the traffic from these clients has this effect on the performance, and what can be done to improve it?

 

[Deleted member 22229]

Could be buffer bloat that is a common problem with many ISP's. When the connection gets near Max for your speed tier it begins to have high pings and latency that causes slow downs and in some cases can cripple the connection until the load is lowered. This is really only a issue when the connection is close to maxed out. Some people use adaptive QOS to limit there speeds to 90% of full and it helps solve the problem. Since your connection is only 6/768 and you have all those devices going at the same time this could be the issue. Here is a test that you can test for buffer bloat to know for sure.

http://www.dslreports.com/speedtest

 

[vrapp]

No, as I said, bandwidth consumption close to the limit is not an issue, while these two applications create slowdown without getting close to the limit. I can start regular download at maximum speed on one computer, see near-limit utilitzation in Traffic Monitor on the router, then go to browse web on another computer; the difference will be there, but very slight. But if iPhone is updating apps, with bandwidth utilization only at 40-50%, the slowdown will be tremendous.

I even made an experiment by using another Torrent client. World Of Tanks updater, one of the two applications having this devastating effect, is using its own torrent client. I tried to download the same torrent with uTorrent, on the same computer, and that had almost no effect on the others.

 

[lord_Galathon]

Maybe your ISP throttles torrent badly and it's affecting your whole WAN. Have you tried just launching a normal legal torrent download to see?

 

[vrapp]

But the same torrent does not present a problem when it's performed by Transmission on the router, or by uTorrent on the same client computer.

Besides, the problem is not with the torrent itself - the torrent goes fast whether it's by WoT's client, or by uTorrent client. The problem is with everybody else in the LAN.

 

[lord_Galathon]

Oh, I hadn't picked up on that. Sorry.