Community discussions

MikroTik App
 
kgninfos
Member
Member
Topic Author
Posts: 387
Joined: Thu Jun 21, 2012 7:34 pm
Location: Earth
Contact:

Wireless Disconnect Extensive Data Loss

Sat Sep 01, 2012 7:30 pm

Hi
i am using Mikrotik RB-411 with Alfa 30dbm Card at both end with 24Dbi grid antenna
both end heights are about 75feet from ground and the area don't have buildings taller than 40feet LOS is almost clear(as seen from google maps)
distance between both end are about 14km
using Wireless G mode with channel 13 (channel 10-13 are free no one using them)

The problem is at day time the wireless link shows 24Mbps/24Mbps up link/down link speed
but at night it's 2Mbps/1Mbps(NOT DECREASING AT NIGHT NOW JUST THE DISCONNECT EXTENSIVE DATA LOSS ISSUE IS THERE)

at day SNR is 25 Db and at night it's about 23-24Db

please help me to find the issue

Thanks
Last edited by kgninfos on Thu Sep 06, 2012 9:59 am, edited 2 times in total.
 
kgninfos
Member
Member
Topic Author
Posts: 387
Joined: Thu Jun 21, 2012 7:34 pm
Location: Earth
Contact:

Re: Wireless link slow at night

Sat Sep 01, 2012 7:34 pm

Just to tell you 5.8 band did not worked
i tried Metal 5SHPN with 29Dbi grid at both end and was even unable to get any signal from one end to other
 
angboontiong
Forum Guru
Forum Guru
Posts: 1115
Joined: Fri Jan 16, 2009 9:59 am

Re: Wireless link slow at night

Sun Sep 02, 2012 6:20 am

check you mounting...
 
kgninfos
Member
Member
Topic Author
Posts: 387
Joined: Thu Jun 21, 2012 7:34 pm
Location: Earth
Contact:

Re: Wireless link slow at night

Sun Sep 02, 2012 6:43 am

check you mounting...
What do you mean??
 
kgninfos
Member
Member
Topic Author
Posts: 387
Joined: Thu Jun 21, 2012 7:34 pm
Location: Earth
Contact:

Re: Wireless link slow at night

Mon Sep 03, 2012 5:42 am

no one can help me??
 
angboontiong
Forum Guru
Forum Guru
Posts: 1115
Joined: Fri Jan 16, 2009 9:59 am

Re: Wireless link slow at night

Mon Sep 03, 2012 1:17 pm

no one can help me??
There's few thing you can do...
1) setup a prtg/ mrtg server and monitor the following thing:
-tx rate
-rx rate
-signal strength

from that, you can see when the signal starting drop and when it's back to normal...
based on that information, and which day will more frequent having that issue, you can pay a visit for the physical checking...

this will be more easy way for you...
 
kgninfos
Member
Member
Topic Author
Posts: 387
Joined: Thu Jun 21, 2012 7:34 pm
Location: Earth
Contact:

Re: Wireless link slow at night

Tue Sep 04, 2012 3:27 pm

tried every thing from replacing the grid to changing the radio
and also from maps and physical verification the LOS is clear

i just can't understand what the problem is

can any one help

i am getting 36Db SNR as of now but the tx rx rate is 11Mbps/1Mbps (i have seen it getting 48Mb/48Mb) many times

Please help
 
wirelesswaves
Member
Member
Posts: 311
Joined: Thu May 31, 2007 12:38 am

Re: Wireless link slow at night

Tue Sep 04, 2012 6:11 pm

Are you actually passing traffic over the link when you see those figures.

Try opening a mac-telnet session between the 2 units, (just so that some traffic is passing between them or use one of the units to ping the other)

Then check those reported rates again (whilst traffic is passing)

Report back on forum.

<Your overall system gain is excessive, that distance can be done with 20dbm +(20db antennas x 2) and still achieve better throughput.>

Simon
 
angboontiong
Forum Guru
Forum Guru
Posts: 1115
Joined: Fri Jan 16, 2009 9:59 am

Re: Wireless link slow at night

Wed Sep 05, 2012 9:19 am

Are you actually passing traffic over the link when you see those figures.

Try opening a mac-telnet session between the 2 units, (just so that some traffic is passing between them or use one of the units to ping the other)

Then check those reported rates again (whilst traffic is passing)

Report back on forum.

<Your overall system gain is excessive, that distance can be done with 20dbm +(20db antennas x 2) and still achieve better throughput.>

Simon
hi...
let try a setting like this, make it running on 11b instead of 11b/g.

if the 11b given you solid 11M/11M with no issue, then you better go for 5Ghz.
 
kgninfos
Member
Member
Topic Author
Posts: 387
Joined: Thu Jun 21, 2012 7:34 pm
Location: Earth
Contact:

Re: Wireless link slow at night

Wed Sep 05, 2012 6:48 pm

i have tried 2Ghz B only and also as told 5Ghz mikrotik Metal 5SHPN but same issues every time
 
angboontiong
Forum Guru
Forum Guru
Posts: 1115
Joined: Fri Jan 16, 2009 9:59 am

Re: Wireless link slow at night

Wed Sep 05, 2012 8:57 pm

Can you probe the signal strength and post the graph here...

Sent from my HTC Incredible S using Tapatalk 2
 
kgninfos
Member
Member
Topic Author
Posts: 387
Joined: Thu Jun 21, 2012 7:34 pm
Location: Earth
Contact:

Re: Wireless link slow at night

Thu Sep 06, 2012 8:33 am

Check this
You do not have the required permissions to view the files attached to this post.
 
kgninfos
Member
Member
Topic Author
Posts: 387
Joined: Thu Jun 21, 2012 7:34 pm
Location: Earth
Contact:

Re: Wireless link slow at night

Thu Sep 06, 2012 9:37 am

UPDATE: after observing for 24 hours the problem was clearly due to the error message "Extensive data loss" not only at night but also at days(i have not noticed it previously)

Please Help
 
Tbird
Frequent Visitor
Frequent Visitor
Posts: 55
Joined: Tue Dec 09, 2008 8:32 pm

Re: Admin Please Help - Wireless Disconnect Extensive Data L

Thu Sep 06, 2012 9:48 am

A 1-2 dBm variation in SNR trough the days is well within normal conditions – even 5 would not call for worries. This is just how the atmosphere plays with us – and what is the consequence for you anyway? The fact that the radio rate is adaptive could explain the lower rates at night – simply less traffic, or are you actually experience less throughput at night?

The problem with “Extensive data loss” have been discussed a lot – search the forum for it, and upgrade to latest version.

TB
 
kgninfos
Member
Member
Topic Author
Posts: 387
Joined: Thu Jun 21, 2012 7:34 pm
Location: Earth
Contact:

Re: Admin Please Help - Wireless Disconnect Extensive Data L

Thu Sep 06, 2012 9:58 am

Now data rate don't decrease at night
just the disconnection
tried every thing about the TX power(it's 30 Dbm now)

The RouterOS version is 5.11
 
kgninfos
Member
Member
Topic Author
Posts: 387
Joined: Thu Jun 21, 2012 7:34 pm
Location: Earth
Contact:

Re: Wireless Disconnect Extensive Data Loss

Sun Sep 09, 2012 8:49 am

i am getting error no beacons received now
You do not have the required permissions to view the files attached to this post.
 
kgninfos
Member
Member
Topic Author
Posts: 387
Joined: Thu Jun 21, 2012 7:34 pm
Location: Earth
Contact:

Re: Wireless Disconnect Extensive Data Loss

Sun Sep 09, 2012 3:33 pm

i changed the protocol to nv2 and the link is stable now but the throughput is only 4Mbps
can any one tell me does the 40mhz channel width really increases the throughput

as i am not noticing any difference
 
rmichael
Forum Veteran
Forum Veteran
Posts: 718
Joined: Sun Mar 08, 2009 11:00 pm

Re: Wireless Disconnect Extensive Data Loss

Sun Sep 09, 2012 3:53 pm

i changed the protocol to nv2 and the link is stable now but the throughput is only 4Mbps
can any one tell me does the 40mhz channel width really increases the throughput

as i am not noticing any difference
Change period size to 8 ms and you'll most likely double the throughput from the default 2ms.

Use parabolic dish antennas, if you can, since grids are more prone to interference. Also, if you can afford for the link to be down, run spectrum scan on each end overnight.
 
kgninfos
Member
Member
Topic Author
Posts: 387
Joined: Thu Jun 21, 2012 7:34 pm
Location: Earth
Contact:

Re: Wireless Disconnect Extensive Data Loss

Sun Sep 09, 2012 6:16 pm

Change period size to 8 ms and you'll most likely double the throughput from the default 2ms.
will try and post the results

Use parabolic dish antennas, if you can, since grids are more prone to interference. Also, if you can afford for the link to be down, run spectrum scan on each end overnight.

i have already tried scan found no interference
 
dada
Member Candidate
Member Candidate
Posts: 245
Joined: Tue Feb 21, 2006 1:44 pm

Re: Wireless link slow at night

Tue Sep 11, 2012 9:36 am

Hi,

1) from the picture I can see that your signal levels are -76/-68 dBm. The -76dBm is quite low for reliable link. When I put your params (30dBm TX, 24dBm antenna gain, 14000m distance) into link calculator I get -48dBm of receive level. So if you have antennas connected with short cables (or even via pigtail only) to the radios you have something terribly wrong with the link.
2) the 30dBm cards looks like an overkill. We have an experience that the RB4xx have troubles with high power cards which cause the box restarts with no obvious reason (maybe the power source module on the board is not able to deliver enough power for the card and the board). And we observe this with DBII cards which should have about 24dBm max TX power. The problem seems to manifest more when you are using low voltage power supply (12V battery backup and so) but we observe it even on 27V.
3) I woulndn't expect much support from Mikrotik for 'non official' wifi card (Alfa card)

IMHO you should check you devices why there is only -76/-68 (the 8 dBm difference is too much too - if there is no reason for it). Then you should check both RB if there are no unexpected restarts (check uptime, check first lines of the log) related to link disconnects. If you solve the problem with the bad signal then you can lower your TX power (which could eliminate restarts if you have any) or even you can use standard wifi card (made by Mikrotik).
 
kgninfos
Member
Member
Topic Author
Posts: 387
Joined: Thu Jun 21, 2012 7:34 pm
Location: Earth
Contact:

Re: Wireless Disconnect Extensive Data Loss

Wed Sep 12, 2012 10:13 am

no restarts are there and i don't know why the system is working like that(Low signal)

previously with TP-LINK 500mw radio the signal margin was 25db and now same with Mikrotik antenna alignment is not changed even a millimeter
 
dada
Member Candidate
Member Candidate
Posts: 245
Joined: Tue Feb 21, 2006 1:44 pm

Re: Wireless Disconnect Extensive Data Loss

Wed Sep 12, 2012 10:25 am

no restarts are there and i don't know why the system is working like that(Low signal)

previously with TP-LINK 500mw radio the signal margin was 25db and now same with Mikrotik antenna alignment is not changed even a millimeter
So you have to check all the components for problems. I would recommend to try to replace them one by one (lightning surge, pigtail, wifi card, antenna cable, antenna) and check whether there is a change. I suppose you are using full TX power settings on the wifi cards
 
kgninfos
Member
Member
Topic Author
Posts: 387
Joined: Thu Jun 21, 2012 7:34 pm
Location: Earth
Contact:

Re: Wireless Disconnect Extensive Data Loss

Wed Sep 12, 2012 11:48 am

i have tried replacing the entire unit one by one but to no worth
and also i am using full tx power at both end i.e. 30 dbi
 
User avatar
NetworkPro
Forum Guru
Forum Guru
Posts: 1370
Joined: Mon Jan 05, 2009 6:23 pm
Location: Worldwide
Contact:

Re: Wireless Disconnect Extensive Data Loss

Fri Sep 14, 2012 10:25 am

Lower the tx power to improve stability.

Are you trying to get Wireless ISP training for your one link by asking 10 0000 questions on the forum? :)

What power supplies are you using? Try chaining those.

Are you using grounded cables and cases?
wiki.mikrotik.com/wiki/NetworkPro_on_Quality_of_Service
 
kgninfos
Member
Member
Topic Author
Posts: 387
Joined: Thu Jun 21, 2012 7:34 pm
Location: Earth
Contact:

Re: Wireless Disconnect Extensive Data Loss

Fri Sep 14, 2012 11:26 am

yes i am using grounded cable
and also i have the tx power set to 19Dbm now but same result
 
dada
Member Candidate
Member Candidate
Posts: 245
Joined: Tue Feb 21, 2006 1:44 pm

Re: Wireless Disconnect Extensive Data Loss

Fri Sep 14, 2012 12:04 pm

yes i am using grounded cable
and also i have the tx power set to 19Dbm now but same result
what is the RX level after you lowered the TX power? If it is different from the calculated value you should solve the difference problem first (IMHO). The difference approx 5 dBm should be OK.
 
kgninfos
Member
Member
Topic Author
Posts: 387
Joined: Thu Jun 21, 2012 7:34 pm
Location: Earth
Contact:

Re: Wireless Disconnect Extensive Data Loss

Fri Sep 14, 2012 2:05 pm

i am getting about 4Db less signal now
 
dada
Member Candidate
Member Candidate
Posts: 245
Joined: Tue Feb 21, 2006 1:44 pm

Re: Wireless Disconnect Extensive Data Loss

Fri Sep 14, 2012 2:26 pm

i am getting about 4Db less signal now
does it mean the RX level is about -63dBm now (since the calculated value is approx -59dBm)?

Now you should check the signal quality. If it is low then you should find why. It may be an interference with another source on the same channel. Sometimes the problem is caused by corrupted wifi card (not able to transmitt or receive the signal properly). Sometimes another part (cable, antenna ,..) can cause this.

A question: do you have only one wifi card in the boxes (routerboard) or there is another card too? In my experience there is always huge interference if 2 cards in the same band are in one routerboard.
 
kgninfos
Member
Member
Topic Author
Posts: 387
Joined: Thu Jun 21, 2012 7:34 pm
Location: Earth
Contact:

Re: Wireless Disconnect Extensive Data Loss

Fri Sep 14, 2012 3:51 pm

i have only 1 card in it
and the signal level is -68
 
wirelesswaves
Member
Member
Posts: 311
Joined: Thu May 31, 2007 12:38 am

Re: Wireless Disconnect Extensive Data Loss

Sat Sep 15, 2012 3:12 pm

stop messing around with all that other stuff and get the wireless side sorted out first and think things through logically.

As I said in post http://forum.mikrotik.com/viewtopic.php ... 11#p296211

You don't need a great deal of maths or experience to figure out that you have a "radio related" error.

You have 14km, from the standard free space loss equation, you can expect -100db at 1st km on 2.4Ghz.

double the distance and subtract 6dB

thus 2km = -106, 4km = -112, 8km = -118 and 16km = -124

Then system gain =

1 at 30db (the TX power of 1 radio card only, the 1 facing the receiver)
1 at 24dB (1 of the antennas)
1 at 24dB (the second antenna)

Therefore system gain = 74dB.

Free space loss = -124dB system gain = +74dB... Therefore expected signal level is around 50dBm.

You have errors of up too 20dB in your system... Maybe you have pigtail disconnected, or maybe you have selected antenna "b" instead of antenna "a" on the radio card. Maybe pigtail is on wrong connector.

Like I said in earlier post,, what you are trying to achieve is possible with much smaller antennas and standard radio cards.. (chuck Alfa card in bin and go back to more regular cards!)

Those cards will give you all sorts of other problems, as well as other operators in your area.

I am sure that when you can get around -50 to -60dbm AT BOTH ENDS then the rest of your problems will go away.

Regards

S
 
kgninfos
Member
Member
Topic Author
Posts: 387
Joined: Thu Jun 21, 2012 7:34 pm
Location: Earth
Contact:

Re: Wireless Disconnect Extensive Data Loss

Sun Sep 16, 2012 3:05 pm

i checked every thing
like the pigtail the ALFA CARD (Tried it with R52 card) everything is ok
i have selected Ant A which is correct

and also the frequency i am using is absolutely free see the attached image
You do not have the required permissions to view the files attached to this post.
 
dada
Member Candidate
Member Candidate
Posts: 245
Joined: Tue Feb 21, 2006 1:44 pm

Re: Wireless Disconnect Extensive Data Loss

Mon Sep 17, 2012 10:38 am

i checked every thing
like the pigtail the ALFA CARD (Tried it with R52 card) everything is ok
i have selected Ant A which is correct

and also the frequency i am using is absolutely free see the attached image
1) the Frequency usage or Scan doesn't guarantee that there is no signal on the same channel (these utilities show only 802.11 sources). Something better is spectral-scan (if you have 5.X ROS and the wifi card supports the feature)
2) I assume you are using default radio channel width (20Mhz). The 2.4Ghz channel schema uses 5Mhz step between channels. So you have to check not only the 2437 channel but the neighbor channels too (it means at least 2437, 2442, 2447 and 2.432, 2427). And even if there is another transmitter on for example 2452 you should know that it will transmit on 2442-2462 so it will interfere with your radio on 2437 - because you overlap with it.


I can see very strong signal on 2452 (Go Wifi at -20dBm) which surely is affecting you radio ...

You can/should:
1) have the RX level (on both ends) as close to calculated RX signal as possible. It looks like you still have problem here.
2) find a channel with best quality (it maybe a problem because I see 2 strong signals in you frequency usage)
3) if you cannot find a free 20Mhz channel you can try to use 10Mhz channel width (but it has max throughput lower by factor 2)
 
wirelesswaves
Member
Member
Posts: 311
Joined: Thu May 31, 2007 12:38 am

Re: Wireless Disconnect Extensive Data Loss

Mon Sep 17, 2012 1:21 pm

I think I would be very alarmed at the -20dbm, -24dbm and the -33dbm signal read from GO-wifi services.

I cannot find out any details of the vendor of that MAC address. I don't recall seeing such levels even when I have experimented with cpe/ap setups in the same office.

Where are their services?, are they on same pole or something. I hope for your sake they are not using overpowered radio cards too and generating unwanted transmissions either side of the intended channel.

Only one other thought, is this service anywhere near a reflective object that could cause a "multipath" scenario. Else I cannot explain the discrepancy in signal level to theoretical level.

I would recommend:

Use one of the Atheros ar9XXX chipsets to do a spectral analysis to determine other transmissions which may not be 80211 compliant.. (or use a commercial analyser or use a ubnt product)

In any event I smell a rat, and I think I would look for another more suitable site that isn't bombarded with such high levels of competitors signals.

I just get a bad feeling for you, and I think that even if and when you do get it to work, I think other problems will come along soon after. And eventually after spending hundreds of hours getting nowhere you may wish that you had found an alternative site long before.
 
kgninfos
Member
Member
Topic Author
Posts: 387
Joined: Thu Jun 21, 2012 7:34 pm
Location: Earth
Contact:

Re: Wireless Disconnect Extensive Data Loss

Mon Sep 17, 2012 3:47 pm

the GoWiFi service is of mine so i will try changing their frequency

also i am using the atheros 9xxx series card
 
wirelesswaves
Member
Member
Posts: 311
Joined: Thu May 31, 2007 12:38 am

Re: Wireless Disconnect Extensive Data Loss

Tue Sep 18, 2012 11:49 am

Ok

So are you saying that you have services on 2462 and 2452 on the same pole.
 
kgninfos
Member
Member
Topic Author
Posts: 387
Joined: Thu Jun 21, 2012 7:34 pm
Location: Earth
Contact:

Re: Wireless Disconnect Extensive Data Loss

Tue Sep 18, 2012 8:52 pm

Yes
 
wirelesswaves
Member
Member
Posts: 311
Joined: Thu May 31, 2007 12:38 am

Re: Wireless Disconnect Extensive Data Loss

Wed Sep 19, 2012 9:29 am

Well, unless you are using a 5Mhz channel width, those 2 services will be interfering with each other.

The bandwidth at 54Mbps is 20Mhz, so services on 2452 will also occupy 2442 and 2462..


regards

S
 
akkinel
just joined
Posts: 4
Joined: Wed Oct 19, 2016 2:02 pm

Wireless Disconnect Extensive Data Loss

Wed Oct 19, 2016 2:13 pm

I Have 2 Mikrotik RBQRTG-2SHPnD
Point 2 Point Link Signal Strenth 64/62
Normaly Link Is Stable But Some Time Link Is Down
Log Is Wlan1-gateway Wireless Disconnect Extensive Data Loss
wlan1-gateway Connected wants bridge

Wireless Ap Config..
Mode bridge
Band 2GHZ Only-n Or B-G-N
Wireless Protocal Nstreem Or NV2
Frequency Mode Superchannel

please help me to find the issue
 
JB172
Member
Member
Posts: 306
Joined: Fri Jul 24, 2015 3:12 pm
Location: AWMN

Re: Wireless Disconnect Extensive Data Loss

Wed Oct 19, 2016 2:30 pm

Check for interference from other Access Points.
 
akkinel
just joined
Posts: 4
Joined: Wed Oct 19, 2016 2:02 pm

Re: Wireless Disconnect Extensive Data Loss

Wed Oct 19, 2016 3:01 pm

Check for interference from other Access Points.
What Sir I Cant Understand
 
JB172
Member
Member
Posts: 306
Joined: Fri Jul 24, 2015 3:12 pm
Location: AWMN

Re: Wireless Disconnect Extensive Data Loss

Wed Oct 19, 2016 3:20 pm

For both sites:
With and without Nstreme/NV2 and for Only-N and B/G/N
From Winbox->Interfaces go to your Wlan and in Wireless tab choose in Scan list->Default and press the Scan button. Check there if other AP have the same frequency or frequency near yours.
You can also press Snooper button.
 
akkinel
just joined
Posts: 4
Joined: Wed Oct 19, 2016 2:02 pm

Re: Wireless Disconnect Extensive Data Loss

Wed Oct 19, 2016 4:03 pm

For both sites:
With and without Nstreme/NV2 and for Only-N and B/G/N
From Winbox->Interfaces go to your Wlan and in Wireless tab choose in Scan list->Default and press the Scan button. Check there if other AP have the same frequency or frequency near yours.
You can also press Snooper button.
I also Try It Change frequency change location tower change hight but sir nothing hight level issue
no one other ap in this frequency
i also try defalut config.
tell me in more config. sir


Thanks
 
JB172
Member
Member
Posts: 306
Joined: Fri Jul 24, 2015 3:12 pm
Location: AWMN

Re: Wireless Disconnect Extensive Data Loss

Wed Oct 19, 2016 4:13 pm

The LOS (Line of Sight) is clear?
When you have disconnections, it rains?
 
akkinel
just joined
Posts: 4
Joined: Wed Oct 19, 2016 2:02 pm

Re: Wireless Disconnect Extensive Data Loss

Wed Oct 19, 2016 4:25 pm

The LOS (Line of Sight) is clear?
When you have disconnections, it rains?
Yes Sir LOS Is Clear
But Nothings Rains Issues
Not Rains In This Sights


Thnks
 
JB172
Member
Member
Posts: 306
Joined: Fri Jul 24, 2015 3:12 pm
Location: AWMN

Re: Wireless Disconnect Extensive Data Loss

Wed Oct 19, 2016 4:52 pm

Who is online

Users browsing this forum: InoX and 51 guests