# Loss of internet connection only when downloading a torrent with a lot of peers



## Uplink10 (Jan 18, 2015)

OS: Windows 7 SP1 updated
Bittorrent client: Bittorrent 7.9.2 (latest)/qBittorrent 3.1.11
ISP internet speed: 100/10 Mbps

Two configurations I tried:







My internet connection is working fine when I am downloading files through FTP, HTTP in both scenarios.

Scenario 1.:

In this scenario my PC is directly connected to a router/switch provided by ISP, I can use two ports because I have assigned two IP addresses.
If I download torrent with little peers (<20) it is working normally. If I try to download torrent with a lot of peers (35<, not including web seeds) it works for a while but then I lose internet connection (it says limited connectivity) and Windows 7 tells me that PC is connected to router (main router in city block not the one ISP installed in my apartment) but it does not have internet connectivity. After a while I get back my connection but then I lose it again sometimes forever and I have to restart my computer.

Scenario 2.:

In this scenario there is TP-Link router between my PC and ISP router/switch installed in my apartment.
In this scenario everything works fine and TP-Link router is a very cheap one 15$.


I do not wish to use 2. scenario because I use a lot of programs for testing and do not wish to manually forward ports every time.
I tried everything there is:
-I updated BIOS, drivers, Windows 7
-limited maximum number of connections in bittorrent application to 100, 50 which is very low
-tried other bittorrent clients

I do not know why I lose internet connection, it should not matter if I have intermediate router (TP-Link) because the router opens the same amount of connections as does my PC in scenario 1.

I would like to know what is causing this and how can I fix my problem in scenario 1.


----------



## AsRock (Jan 18, 2015)

Bypass the router and just directly connect to the modem and see if it still does it, it could be very well your ISP line as a lot don't want to clogging up there network.

Might have to change ISP or a higher tier from them to handle all the connections.


----------



## hat (Jan 18, 2015)

I think your router (the one from the ISP, that is) is crapping out under the strain of all those connections. I had a router once that when I used utorrent, I wouldn't lose connection but I would get some pretty bad lag while gaming, even though I limited the bandwidth it would use pretty well. Turns out it was all the connections bogging it down. I further tweaked my settings so that each torrent had few connections available, and all was well.

Use the TP-Link router. If you do not wish to forward ports, put your computer in the DMZ. The DMZ is a slot in the router any one computer can go in where all the ports are wide open, as if it was connected directly to a modem. This is bad for security, but if you can't be bothered to manually forward individual ports, that's the way.


----------



## Uplink10 (Jan 18, 2015)

AsRock said:


> Bypass the router and just directly connect to the modem and see if it still does it, it could be very well your ISP line as a lot don't want to clogging up there network.



I am sorry, I do not know what you mean, I cannot bypass "ISP router/switch" in my apartment because through it I connect to ISP and subsequently to WAN. If you meant TP-Link router I am already bypassing it, I just gave an example where everything is working if I have a router between.



> Might have to change ISP or a higher tier from them to handle all the connections.



If I have TP-Link router between everything is working normally so the problem might be on my end.


----------



## brandonwh64 (Jan 18, 2015)

hat said:


> I think your router (the one from the ISP, that is) is crapping out under the strain of all those connections.



This is exactly the cause. I went through 3 wireless routers doing the same thing and then I decided to build a custom router and have had no issues since.


----------



## Uplink10 (Jan 19, 2015)

@hat

I am going to try limiting connections to very few (30). On a side note, previously when I limited download speed to 500 kB/s this was still happening.

I would rather not use TP-Link router because in my situation it is very inconvenient.

@brandonwh64

But my PC (Scenario 1.) makes the same amount of connenctions as does my Tp-Link (Scenario 2.) router, but for some mysterious reason it only works with TP-Link router. And this router from ISP (by a company I think Milan Technology) is not exactly an usual router because it is more like an optical fibre to UTP cable switch:
-it is without web interface
-can be configured only through serial port (RS-232)
-TV and phone are connected to this router/switch through RJ45 port

My professor at school told me that it is not a modem but a router since it only routes my connection to ISP`s main city block router. But it can be viewed as a modem since I cannot bypass it.


----------



## Uplink10 (Jan 19, 2015)

Update 1:
I found out that if I limit connection count  to:
-20, 30, 50 = it works but download/upload speed is too small for me and I need to establish more connections for faster download/upload
-100< = I lose connection

I think the answer is somewhere in Windows. If I could convince/set Windows to act more like a router than a PC connected to router ( I disabled UPnP and NAT-PMP but nothing changed) then maybe it would work. I also found out that the loss is very spontaneous, right now I have 200 connections and seems to be working, but it will probably stop after a while.

Update 2: Now I lost it again.

Update 3: Here is a picture of a connection loss/timeout


----------



## jboydgolfer (Jan 19, 2015)

Im uncertain as to weather You have explored this option, but I've noticed that in the older versions of uTorrent , back from when I used to torrent I would drop from 7-10Mb/s all the way down to 12Kb/s.....or to 0kb/s....I THOUGHT it was My connection, but it turned out to be "Disk Overloaded"... with writes or what have You. Dunno if That might be Your issue, or if YOur certain it is NEtwork based, but I figured it couldn't hurt to mention....I just remember troubleshooting it for a while, then realising that down in the bottom left corner it said my disk was overloaded...I felt like a fool for missing it, but i usually miss the obvious things. My HDD wasn't slow either..good luck either way.

As others have mentioned as well, Your ISP could very well be throttling You when Your draw becomes higher than what they deem is "acceptable".


----------



## Uplink10 (Jan 19, 2015)

@jboydgolfer
I monitor my disk usage regularly because I really like my HDD (HGST 7K1000) and want to see how it performs and I can say for sure that HDD is definitely not a problem.

I also think that if I would use VPN my connection would be okay because it would be wrapped in a tunnel and it would not maybe put a strain on ISP router.


----------



## FireFox (Jan 19, 2015)

I didn't read the whole thread because I am at work and i don't have too much time, what about scenario 1 without ISP router and instead  just using T- link.


----------



## CounterZeus (Jan 19, 2015)

Be sure to limit the amount of half-open connections as well.


----------



## hat (Jan 19, 2015)

Well, you have to either limit your connections to where it doesn't overload the router, or use the TP Link router (or find another router that you would like better).


----------



## FireFox (Jan 19, 2015)

hat said:


> or use the TP Link router (or find another router that you would like better).


+1 that would be the best solution.
Btw take a hammer and hit your ISP's Router two or three times maybe that would help.


----------



## Aquinus (Jan 19, 2015)

I had a D-Link router that would restart if there were too many peers. I suspect it's probably the router getting overwhelmed by the number of simultaneous connections.

Also: Don't use more than 5 upload slots. If you have 50 people uploading off your connection you'll probably saturate your upstream which will destroy your downstream.

Start simple: No download limit, 100KB/s upload limit, 100 peers, 5 upload slots if it lets you set that.

I run Transmission Daemon on my gateway server, so I use Transmission Remote GUI to access it from my towers. These are my settings for my 120/14 connection.


----------



## Uplink10 (Jan 19, 2015)

Knoxx29 said:


> I didn't read the whole thread because I am at work and i don't have too much time, what about scenario 1 without ISP router and instead  just using T- link.



Well my ISP router is mandatory since it  is like modem if I would have broadband, the ISP installed it in my apartment and it is not the usual router because it does not have web interface you can only configure it through serial port, read above I explained it.

@Aquinus

I use NetLimiter to not clog up my download rate with too much upload. I also experimented with Deluge deamon and it is great, it beats every WebUI available.

But I still want to know why can not the mandatory ISP router (more like UTP cable to optical fibre switch) accept my connections from PC and keep them up, why does it work when I have TP-Link router between?


----------

