Wireless Errors at High Load

[jimf]

Greetings,

I'm running 376.49_4 on an AC68-R. I'm trying to run Drive Snapshot backups across wireless and I'm having trouble. Drive Snapshot runs disks and networks hard, so it tends to find problems.

In a nutshell, the problem is that various errors occur at various points in the image check (sometimes just checksum errors, sometimes a windows handle is lost). This works fine on wired connections and fails on wireless connections. I've tried this on 3 routers and 2 computers and the common failure point seems to be the AC68 on wireless.

I've looked in Windows event logs and the AC68 Syslog and have found no recognizable errors at the timeframes this occurs. Just looking for any other things to look at or any settings in the router to change.

The only other item of interest is that throughput (as mesasured by LAN Speed test) shows something on the order of 60Mbps for writes to the server and 20 Mbps reads from the server (the server is wired). This seems like quite a difference and checking the image is essentially lots of reading.

It's not a terribly big deal since backups over wireless aren't exactly critical and I can use a wired connection for that.

Merlin, thanks for doing what you do. I upgraded from _42 yesterday with no issues at all (the behavior above has been happening with _42 as well).

 

[john9527]

Something you might try. I run custom scripts using wbadmin to do backups over wired, 2.4GHz wireless and 5GHz wireless and was experiencing the same random errors on the wireless backups. While searching, I ran across some documentation that the Windows master browser election process can cause a disruption in wireless communications. So, I did the following:

- Set the router to 'Force as Master Browser' under USB Apps/Samba (I also made it the WINS server)

- Ran the following reg file on the wireless clients to prevent them from participating in the Master Browser election (the default is "Auto")

REGEDIT4

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\Browser\Parameters]
;"MaintainServerList"="Auto"
"MaintainServerList"="No"

No more problems and things have run clean since.....

 

[jimf]

Thanks for the tip. I tried all that and even made your changes to all PCs on the wireless network, but the problem persists. I'll keep futzing around but it seems to be stabs in the dark at this point. (Router settings were already in place).

I sort of had doubts about this particular solution since it does work on an old Linksys WRT54G and a TPLink WR941 with stock firmwares. (I seem to be accumulating routers).

Any performance flags I could disable, maybe? This is on both 2.4 and 5Ghz -- I don't know if there is any commonality that could be addressed with settings.

 

[john9527]

Sorry the Master browser didn't help. The only other things that immediately come to mind....

Wireless/General
Uncheck the 'Optimize for XBox' I've had some strange things with that checked (I don't have an Xbox, so may not be a good choice for you)

Wireless/Professional
Disable 'Roaming Assistant'
Disable 'Enable WMM APSD'
Try both Enable and Disable for the Beamforming options - this can be very client dependent

 

[BWR]

You could also try disabling the power saving setting on the clients' wireless cards.

 

[jimf]

RESOLVED! After more experimentation, I realized that the speed losses were when moving traffic over wireless <-> wired. Wireless <-> wireless seemed to have good speeds. Resolution was factory reset, reflash, factory reset, enter settings by hand. Restoring settings from the prior.cfg file hosed this up every time.

Speeds now are about 65 Mbps upload, 100 Mbps download on N network with link speed of 300 Mbps. I consider 25% to 50% of link speed in actual throughput to be in the normal range (despite what marketeers say), especially since I don't sit right next to the router.

Backups are now verifying fine over wireless in about 25% of the time it used to take.

Thanks to everyone of their suggestions.

 

[noric]

Speeds now are about 65 Mbps upload, 100 Mbps download on N network with link speed of 300 Mbps.

Are these speeds on the 5GHz network or on the 2.4GHz?
Thanks.

 

[AdvHomeServer]

RESOLVED! After more experimentation, I realized that the speed losses were when moving traffic over wireless <-> wired. Wireless <-> wireless seemed to have good speeds. Resolution was factory reset, reflash, factory reset, enter settings by hand. Restoring settings from the prior.cfg file hosed this up every time.

Speeds now are about 65 Mbps upload, 100 Mbps download on N network with link speed of 300 Mbps. I consider 25% to 50% of link speed in actual throughput to be in the normal range (despite what marketeers say), especially since I don't sit right next to the router.

Backups are now verifying fine over wireless in about 25% of the time it used to take.

Thanks to everyone of their suggestions.

Thanks for the full story. I suspect you encountered a generic problem and found a generic solution. Basically, if something doesn't work as common sense says it should, reset, reflash, and DO NOT reload from the saved cfg file. I'm going to file that one away for future reference.

In my blog, I mock some forum advice (not from here) about being the equivalent of reformat and reinstall. In this case, that really was the correct solution. Live and learn.

 

[jimf]

The PC I'm using is only N-capable. Link speed is 300Mbps.

2.4 Ghz gives about 60 upload, 100 download

5.0 Ghz gives about 75 upload, 55 download

I'm about 40' from the router and it is in a very noisy brick wall corner (aka the "Network Closet") sitting beside a cable modem, ooma device, and a 24 port switch within a foot of it -- with some regular wood framing and a chimney in the way, I don't expect exactly blazing speeds (but error correction is a requirement).

When I went through all this, I played with inSSIDer and discovered I have no overlap (I'm in a home with a big yard, so neighbor's RF is seldom a problem).

 

[jimf]

Thanks for the full story. I suspect you encountered a generic problem and found a generic solution. Basically, if something doesn't work as common sense says it should, reset, reflash, and DO NOT reload from the saved cfg file. I'm going to file that one away for future reference.

In my blog, I mock some forum advice (not from here) about being the equivalent of reformat and reinstall. In this case, that really was the correct solution. Live and learn.

Well, I had an unknown problem and was desperate .

Once I figured out that the problem was the linkage between wired and wireless, it seemed to make more sense to pull the nuclear option since there is not much of a way to influence that with settings (to the limit of my knowledge, at least). A test just after the reset (which was successful) proved to me that something was hinky in the settings restore.

I now have a 12 page Adobe document of screen prints that represents what I care about in router setup (i.e. where I changed defaults), which I made after I restored the config and broke it. I followed those pages carefully after the next factory reset, so it was probably not a setting, per se. That document now lives in the Router Backups directory along with setting .cfgs and old firmware.

 

[jimf]

To anyone still following this, if I would have done what's in the thread below instead of using a .cfg file for the restore AND did a factory reset after installing but before restoring, I don't think I would have had the problems I encountered. I didn't know using .cfg files was bad practice between firmware versions.

http://forums.smallnetbuilder.com/showthread.php?t=19521

Thanks again john9527.