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Baud1200

join:2003-02-10
Reviews:
·Shaw

4 edits

Modem requires reset after heavy useage to get speed back??

Figure that this is the place to get some additional insight into anything that i may have missed. with this issue, and to see if anyone else is experiencing a similar issue with modem slowdown, requiring them to reset it to re establish previous performance levels.

Problem:
Internet performance after heavy torrenting (p2p). Plan: Unlimited 250 - Modem Cisco DCP3825 (bridged)

Wiring Config
»imageshack.us/a/img26/7784/lanw.jpg
All hardware (modem and switch included) are powered through battery backup/power conditioning devices.

Hypotheses:
After configuring a test client to run as a torrent server, it appears that after letting it run for a full nite, adversely affects either:

a)the modem hardware itself.
b)Physical wiring of the cable (bad ground Ie.. others)
c)establishes that this IP is heavy on P2P and Shaw traffic shaping is effectively added.
d)other ISP's with clients that connected to my server ALSO restrict/shaping my IP for anything that goes through them after one of their users connects to me.
e)torrent server software error (Utorrent and Bittorrent both software attempted)
f)Physical PC hardware error (though replicated on 2 different PCs)

Now, before everyone points to the router in the above diagram... Results are identical if router is eliminated and server is hooked directly to the modem with second IP enabled to test for any slowdown after full nite of running.

Solution??
Usual fix is to unplug the cable modem for 1-5 minutes and then plug it back in, the issue seems to dissapear until l leave the torrent server up again for a nite. Since restarting the modem usually yields the same IP, it tentatively rules out some of the above and thus leads me to believe its an issue with that amount of connections (20,000+ states) overloading the Shaw modem in the same manner it would a cheap home router, forcing a reset to bring it back to default performance levels.

Any insight into this would be appreciated, as i am at my wits end trying to figure out what is going on now, but it seems to be getting worse especially in the last 2 months, as even Shaw's own speedtest shows 130-150 in this situation where normally it shows up to 220, still far from the 250 I pay for. When you look at it objectively that 100MB difference is 2x50MB plans that people pay good money for.

Playing Black Ops, Diablo III and GW2, and also getting flat out disconnects from the game servers themselves. I put up with it for a while now hoping it would get better but its getting worse. I hope its not network saturation now that more and more ppl are getting on the faster plans or will have to swap to Telus just for a cleaner gaming connection


kevinds
Premium
join:2003-05-01
Calgary, AB
kudos:3

If you leave it sit, without rebooting it, but keeping the torrent applications shutdown, do your speeds return to normal after a period of time?
--
Yes, I am not employed and looking for IT work. Have passport, will travel.



TorLOL

@shawcable.net
reply to Baud1200

Torrents... Thats the issue, waste of upstream bandwidth!


mike10

join:2004-03-02
reply to Baud1200

Are you downloading HBO shows from public trackers I have heard about problems like this from people that do that


ilianame

join:2002-06-05
Burnaby, BC
kudos:1
Reviews:
·Shaw
reply to Baud1200

I've always noticed performance drops with Shaw on high connection counts.

At some point I had 2 Shaw lines to allow myself a gaming line, while the other line is Torrenting.

I've since "solved" the problem by not having that many connections (basically not using any public torrenting anymore)

I think this is a problem of DOCSIS encapsulation on the CMT end. As the IP equipment CAN handle 20k connects, but every time I'd go over 200+ on Shaw it would bring the line to a crawl.

It never happened on Novus - as you are plugged in directly into commercial grade IP infrastructure...

It is a battle I have forsaken (and by passed)


ravenchilde

join:2011-04-01
kudos:2

said by ilianame:

I think this is a problem of DOCSIS encapsulation on the CMT end. As the IP equipment CAN handle 20k connects, but every time I'd go over 200+ on Shaw it would bring the line to a crawl.

I don't understand if you are blaming the Cable Modem or the CMTS...

ilianame

join:2002-06-05
Burnaby, BC
kudos:1
Reviews:
·Shaw

Both... You don't hit TCP IP network until you are through the DOCSIS encapsulation which happens between the Modem and the CMTS.

And I'm alleging that the encapsulation process is not as high speed / high throughput as the TCP/IP network equipment.


ravenchilde

join:2011-04-01
kudos:2

said by ilianame:

And I'm alleging that the encapsulation process is not as high speed / high throughput as the TCP/IP network equipment.

On the CMTS it's done at line rate on hardware FPGAs (or ASICs). Remember that a CMTS is "Carrier Grade", and heavier duty (and price tag) than enterprise networking gear.

Modems are cheaper CPE equipment, I can't really speak to them. There are a few chipset vendors out there with differing hardware.

tlhIngan

join:2002-07-08
Richmond, BC
kudos:1
reply to Baud1200

TCP shouldn't matter at all as the CMTS and modem only deal with IP packets from that point - they don't care what's being encapsulated by the IP packets - TCP, UDP, ARP, whatever.

Perhaps what happens is you didn't ratelimit your uploads and your modem started buffering upload packets. When this happens, it dramatically increases the latency (easily seconds for upstream packets). This will make the internet seem slower. Resetting the modem clears the buffering.

Try limiting your torrent uploads to say, 80% of your maximum upstream (this gives you extra bandwidth to do other stuff at the same time)...


ravenchilde

join:2011-04-01
kudos:2

said by tlhIngan:

Perhaps what happens is you didn't ratelimit your uploads and your modem started buffering upload packets. When this happens, it dramatically increases the latency (easily seconds for upstream packets). This will make the internet seem slower. Resetting the modem clears the buffering.

Bufferbloat... if you are running a tomato or DD-WRT router you should try installing a firmware with CODEL as the TCP congestion avoidance mechanism. Should fix buffer bloat.


Jumpy

@shawcable.net

He's already using a non-standard router (an HP Proliant according to his diagram). Perhaps there's another queueing scheme he can use without all the work of deploying CODEL (he'd need Linux 3.5 or newer/custom compiled older, from what I recall, and something like iptables, since (X)-WRT isn't designed for larger-scale platforms like his).


tlhIngan

join:2002-07-08
Richmond, BC
kudos:1

The easiest way is to just limit the upload rate as an experiment. Requires doing nothing other changing a couple of settings in the torrent client.



Baud1200

join:2003-02-10
Reviews:
·Shaw

4 edits

1 recommendation

reply to kevinds

As usual, the regulars on this board have been more than impressive. Not a single idiot or troll reply. Though i've been away for a while I still managed to get a few more tests done in between runs up north :P will try to answer any questions and clarify a few things that i was not specific enough on.

said by kevinds:

If you leave it sit, without rebooting it, but keeping the torrent applications shutdown, do your speeds return to normal after a period of time?

Nope not untill I reset the modem. (just tested this for you after 4 days running).

said by ilianame:

...
At some point I had 2 Shaw lines to allow myself a gaming line, while the other line is Torrenting....

Strongly leaning towards this for reasons below, though the second line wouldn't be from Shaw.

said by tlhIngan:

Try limiting your torrent uploads to say, 80% of your maximum upstream (this gives you extra bandwidth to do other stuff at the same time)...

I wish it was an issue.. while speedtest posts upload of 13.5Mb i have left the thing running all nite after looking at the logs it never broke 400K/sec and still has the same affect. what seems to be happening is many north American clients even with dsl and cable are connecting and getting terrible transfer of 1-8K/sec.

As background I pay for this unlimited 250 package for one reason. to get the 15Mb upload to serve unlimited torrents without hassle. I don't serve any copyright content at all, yet i have 30 some private media files serving on this line, and i can't grasp the fact that when a friend from Dallas connects he cant get more than 2Kb/sec from me on his Comcast cable modem.

Since it seems that its pretty much impossible to saturate this 15Mb (13) unless you get a client connecting to you with native IPv6 which is not filtered from either ISP, you wont get even close to 10Mb/sec of the other unlimited plan. Thus downgrading to the unlimited 100 and getting a telus line purely for gaming seems like the solution. Of course, I could try to swap to the business package that shaw offers for my torrent connection but i have a sneaking suspicion that all of a sudden it will work properly, putting me over my allotted usage and allow them to bill me more. As a home user (non buisness) based package i really don't understand what they want us to transfer files with if they limit every single peer to peer (non commercial) software, how does this make sense for a non commerical package? With this being the best of the best as far as knowledge base, i still can bet that not a single person can even name me a P2P software that is not effected... Really seems to me like most major ISP's are promoting (by difficulty using anyting else) major cloud based solutions that can nanny your content; really don't like where this is headed.

said by Jumpy :

He's already using a non-standard router (an HP Proliant according to his diagram). Perhaps there's another queueing scheme he can use without all the work of deploying CODEL (he'd need Linux 3.5 or newer/custom compiled older, from what I recall, and something like iptables, since (X)-WRT isn't designed for larger-scale platforms like his).

Its a Proliant running the latest dev. build of PFsense.