Another Internet Crashing Problem

[JanChang]

I understand that this is kinda an annoying post appearing every a short period of time. I have read some posts in this forum associated with the same problem, but none of them can fix my problem efficiently.

Here is the story. I used to use BitComet to download BT files. It worked really great for several years. Probably from last month, or a bit earlier, both the BitComet download and my internet completely crashed after the initiation of BitComet downloading for about 20 to 30 minutes while I basically didn't change any setting (but during this 20 to 30 minutes, BitComet download seemed normal and fast). This terrible situation had never been better since then. I thought it could be a software problem and switched to uTorrent 1.8 Beta. Again, over the first 20 - 30 minutes, the download speed was so fast when I monitor the speed sheet that I even thought my BT download would be back to normal. However, after the darn 20, 30 minutes, the speed curve suddenly dropped down to near 0 in just few seconds and I saw a triangle with an exclamation mark inside saying my internet is disconnected.

I've tried it for many times, playing around with different settings but all got the same result - uTorrent download and internet both crashed after about 20 minutes. I decreased my Global Maximum Number of Connections to 200 and lower as some people suggested in similar posts. I also set the number of half-open connections to 8 and lower. I even turned off all my firewall and anti-virus software while using uTorrent. But none of above can stop, or even improve, the internet crash. I thus always have to unplug my modem, router, and restart my PC to reset my internet.

I here list some of my hardware, internet and uTorrent settings.

Cable provider: Comcast

Modem: MOTOROLA SB4100 Cable Modem

Router: LINKSYS BEFSX41

Connection speed: ~9000kb/s (download); ~920kb/s (upload)

Operation system: Windows XP (SP2)

Anti-virus software: BitDefender Antivirus 2008

Firewall: Windows Firewall

(P.S. My internet is wired, not wireless)

uTorrent:

Global Maximum upload rate: 90kb/s (tried 50 and lower, still disconnected after 20 min)

Global Maximum Number of Connections: 250 (tried 200 and lower, still disconnected after 20 min)

Maximum Number of connected peers per torrent: 150

Number of upload slots per torrent: 6

Maximum number of active torrents: 4

Maximum number of active downloads: 3

net.max_halfopen: 8 (I used Even ID to change my Windows maximum half-open number to 100)

Protocol Encryption: Forced

UPnP port mapping: unchecked

DHT I have tried checked and unchecked, both cause internet disconnection.

I will probably try directly connect my internet to the modem without a router tonight; hopefully it would work this time. Anyhow, I really hope somebody can help me with this problem. It's a suffering to me can't download BT files. Thanks for your patience for reading the tedious post.

[Ultima]

Hm. This one looks tough, as you seem to have most of the bases covered. Connecting directly to the modem is indeed a good idea.

Also, try uninstalling BitDefender (temporarily) just to make sure it's not doing anything stupid.

[Switeck]

PROBABLE TROUBLEMAKER! : MOTOROLA SB4100 Cable Modem

This thing will go into a pseudo-router firewalled mode for no apparent reason and crash under high loads.

DHT, LPD, UPnP, Resolve IPs ALL need to be disabled...as they create additional connections which may aggrievate your problems.

You're going to have to cut back on these settings:

Global Maximum Number of Connections: 250 (tried 200 and lower, still disconnected after 20 min)

Maximum Number of connected peers per torrent: 150

net.max_halfopen: 8 (I used Even ID to change my Windows maximum half-open number to 100)

...To something like this:

Global Maximum Number of Connections: 50

Maximum Number of connected peers per torrent: 35

net.max_halfopen: 4

*IF* that works, you can try adjusting those numbers upwards until crashes start occurring again. Then find an in-between value where crashes are rare to nonexistent.

I'm on ComCast as well, and sadly found that I can no more allow incoming legacy connections...and must use forced encryption outgoing if I want to retain connections to peers while seeding.

[JanChang]

I tried to use Switeck's Recommended uTorrent settings: http://forum.utorrent.com/viewtopic.php?id=34259 of 900bps upload speed the other day, it miraculously worked for the whole night and my internet didn't get crashed. However, when I continued to use the same settings the second day, the connection was dead again. I then tried 800bps upload speed and even lower speed settings the following days, but never got it work again. I totally have no idea why that particular day everything was successful. Now the situation is worse. I said in my first post that my BT download could last at least 20 minutes and then crashed; the duration now dropped down to only 5 minutes. That's fxxking frustrating! I really hope somebody can help me here.

[Switeck]

You may have hostile software on your computer causing the crashes, or your modem is dying.