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Master_Scythe

Wireless dropouts

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So, I get wireless dropouts. Annoying ones. The rest of the router is unaffected.

Its a Billion 7800NL, and syncs well (i really don't want to replace it, due to the SNR tweaks....).

 

basically, every 10 minutes or so, the wifi 'turns off' and comes back 3 seconds later. I have a 'fix' but it breaks other things.

 

 

Basically if I drop my DTIM to '1'

and Drop my Becon below 101, this wifi 'reset' happens.

 

 

IF, however, my DTIM is set to '2'

AND my beacon interval is about 105, its stable.

 

 

Only problem is, trying to stream media, my wireless adaptors don't like that setting.

I get perfect streaming at DTIM 1, Beacon 80, but dropouts.

I have the rate locked at 48mbps for N and G.

 

WMM off helped, and QoS is disabled; Max clients is set to '4' (I have 2 devices on wifi at any time)

 

I know those settings shouldnt have an effect on throughput or anything, but for some off reason it does (beacon set to 50 on other brands helped apple devices hold connection. Its quite well documented.)

 

Also, after seeing this thread, I think I'll be opening it up:

http://forums.overclockers.com.au/showthread.php?p=15389638

 

get some isopro on the wifi card contacts, and make sure all my heatsinks are firmly secured.

 

Ive been reading something about broadcom wireless having issues with 40mhz mode? which it's currently set to..... anyone know anything about this? I'll try forcing 20mhz tonight.

 

IF that fails, I'll be disabling wireless and using the DDWRT box I was going to use as a project. Its TP-Link and, as per my love letters on this forum, TP-Link has NEVER let me down yet.

 

EDIT: on further research, it seems this 40mhz bug is WELL known, and VERY severe..... it could easily be my problem.....

Edited by Master_Scythe

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So, yes that's the solution.

 

dropping the rate to 20mhz has made the connection rock stable. This is a widespread issue and well documented when you look for it; but seems oddly secret to the greater community.

 

It affects all consumer level broadcom chipsets (some worse than others). and results in wifi 'crashes'.

I also removed the top of my router, and it wont be going back on. Massive airflow FTW.

 

Also, interetingly, the Broadcom WIFI chip was finger scaldingly hot even at idle, and had no heatsink.

I stuck a pure copper ramsink to the chip, and hopefully it's helping.

 

between the heatsink, and the 20mhz; Ive been able to drop my DTIM to 1 and my beacon to 80, which keeps my wifi dongles from having to 'research' every 5 minutes. Stable, and my Crunchyroll anime can stream fine now.

 

Hopefully this bug\fix helps someone else out.

And if you have a 7800NL, get a ramsink for that wifi chip, its BURNING. Also those caps are..... shit...... lol; keep an eye on bulging.

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So, I get wireless dropouts. Annoying ones. The rest of the router is unaffected.

Its a Billion 7800NL, and syncs well (i really don't want to replace it, due to the SNR tweaks....).

That's why I keep separate gateway and wifi devices.

 

I have an AirPort Extreme as my gateway (it was the fastest WAN-LAN throughput at the time, but soon to be replaced with an EdgeRouter Lite http://www.ubnt.com/edgemax#edge-router-lite ), and a Linksys E3000 for wifi, which I'll soon be replacing with a UniFi AP AC: http://www.ubnt.com/unifi#apac

Edited by SquallStrife

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I purely run one for power savings, and because I have another 2 running in the same cupboard for the 3 seperate internet connections that run into my unit.

Breaking the wifi to its own router would be painful :P

 

Its amazing to see the router is only a single board; only 3 visible chips.

 

a CPU (covered by heatsink)

a memory chip (samsung)

a broadcom chip (wireless)

 

the CPU probably handles the DSL too, who knows whats under there.

 

I was also shocked to see no form of heatsink on the broadcom chip. I mean, sure, there are times when you go overboard, but I dont think any chip thats able to instantly burn you, can be too happy?

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Such an AP wouldn't be in your cupboard, it's ceiling mounted for better coverage.

 

But yeah, less devices is advantageous.

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its in my cupboard because being all in one, I made a custom 5cm phone line for it.

 

Tempted to take the socket out of the wall and direct crimp an RJ11 to it honestly...... one less pair of joins.

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its in my cupboard because being all in one, I made a custom 5cm phone line for it.

Such an AP wouldn't also be your ADSL modem, so that's not a problem.

 

Tempted to take the socket out of the wall and direct crimp an RJ11 to it honestly...... one less pair of joins.

Oh god. Don't.

 

I can understand gluing a heatsink on to a router ASIC/SoC for some obsessive "because I can" type reason.

 

But don't go breaking the law for no reason. The practically nonexistent benefit would be far outweighed by the potential penalties.

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Yeah purely out of lazyness I dont think I would. Though I am telstra licenced, so no law problems.

 

and its not obsessive :P that thing was well over 100deg to instant burn, no chip 'enjoys' being that hot! I dont want my modem to die, and heat coulda easily been affecting the broadcom wifi chip.

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Though I am telstra licenced, so no law problems.

Telstra don't issue licences to work on house cabling, ACMA does.

 

It's a registration that not only requires on-the-job training and experience to obtain, but requires more of the same to maintain.

 

So unless you're basically an electrician between your PC fixing jobs, I'm sceptical that you're legally cabling up your house.

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Fair cop. I haven't read what was required to maintain it. In 2009 I was working with, and got certified in, installing phone lines from street, to property. And in adding additional cabling to an existing phone network (was doing BIIIIG PBAX system installs in offices; those things are archaic and anything 'good' you can do with them requires terminal access; blech!). But yeah, once that job finished, I basically ignored that one. lol, so easily expired. IF that required a full electrician, then that would explain why my work was always checked over and signed off by the boss man, not myself. I should go find my papers; see what I was actually allowed to do. Maybe it was for pit work?

I was young, and my job was the last thing on my mind, honestly.

 

 

Anywho back on topic; what I'm not, is aware of what temperature is required for 'instant burn'? I didnt blister, but I had a reminder all night that I'd put my finger on that Broadcom chip. I'm sure there's a temperature for that? Anecdotal evidence online suggests 100deg? Surely there isnt a chip on earth that LIKES running this hot?

 

All I'm trying to figure out was if my urge to heatsink it was justified, or if my obsession with heatsinking chips that make heat just took over :P lol

Edited by Master_Scythe

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Anywho back on topic; what I'm not, is aware of what temperature is required for 'instant burn'? I didnt blister, but I had a reminder all night that I'd put my finger on that Broadcom chip. I'm sure there's a temperature for that? Anecdotal evidence online suggests 100deg? Surely there isnt a chip on earth that LIKES running this hot?

 

All I'm trying to figure out was if my urge to heatsink it was justified, or if my obsession with heatsinking chips that make heat just took over :P lol

It doesn't take 100 degrees for a surface to be painfully hot.

 

60 degree water is hot enough to scald, and that's only hot water from the tap, not even from an urn or similar.

 

Modern processors have pretty high thermal envelopes. Most laptop CPUs sit around 80-90 degrees under load, quite normal.

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I was led to believe, although tolerances are well within range, that a hot chip was more likely to misbehave (for various reasons) the hotter it was?

 

This modem is at least 3 years old, with 3 people hammering it HARD for its whole life. Is it possible due to age and stress it doesn't like that much heat? Or have I been told wrong? I never did actually backup what I was told on this topic with research.

Edited by Master_Scythe

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If a chip "misbehaves" within its operating temperature range, then it's faulty. Look up the datasheet for the IC in question.

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Age and levels of stress\use has no effect?

 

and i shall go look it up now :D

 

*google*

 

+85deg MAX

 

not ALL that helpful without knowing what the actual chip temperature was. I knew I shoulda bought a laser thermometer a few weeks ago.

Edited by Master_Scythe

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Parts like that usually have an MTBF that roughly accounts for most usage cases across the range of operating tolerances.

 

For instance, imagine a part that has an MTBF of 100,000 hours, and an operating temperature range of -10 to 70 degrees.

 

If you run the device 24/7 at 69.9 degrees, then you shouldn't bank on getting more than the 100,000 hours, but at the same time it should still work properly and fullfill the MTBF figure, because you're using the part as specified by the manufacturer.

 

Once you go outside the operational limits, then all bets are off. You might be lucky and get a sample that gives you the full 100,000 hours running at 85 degrees without issue, or you might be unlucky and get one that stops working after a few hundred hours at just 75 degrees. It's all based on statistics, and is influenced by how many sigmas of quality the manufacturer works to.

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Thanks for the explanation. Whats the quality like though? Is the MTBF to be believed these days? Are companies over-stating them in order to appear better than the competition? Or is this not happening on the IC level yet.

 

Right. So locked in a sealed cupboard, with 4 other routers, all pumping out heat, on 45 degree days, for 3 years, could have easily shortened its lifespan.

In the end, all I know is that heatsink is FUCKING HOT, and that means that heat isnt in my chip anymore.... and this makes me happy. lol

AND I get no wireless dropouts.

 

tis a good thing :P

Edited by Master_Scythe

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hmm, I have the same model but haven't noticed any wi-fi dropouts.

 

Are those settings you mentioned the defaults or things that you've tweaked?

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