Wireless Troubleshooting

RouterOS Wireless Networking
1

Hi,

Is there any way to know which site have problem.

At the beginning, this link was very solid (TX/RX CCQ 95%-100%), but suddenly the link drop very bad.

Is the problem at AP site or Client site ?
At AP site: Overall TX CCQ: 100 % ; Signal Strength -87dbm ; Noise Floor -106 dbm.
At Client site: Overall TX CCQ: 22 % ; Signal Strength -72dbm ; Noise Floor -90 dbm.

I already replaced device (RB+Card) at Client site, but problem still same.
Already changed frequency, still same.

Is it antenna / pigtail problem in client site ?
or
Problem in AP site ?

Please help me to solve this problem.


Regards,
Yujobika

2

Problem is in client side. Look at the noise floor..

Try to change polarity from vertical yo H or H to V and try 2 or 3 freqs. It should be better..

3

If not, try to disable csma in wireless

4

I run an hourly SNMP scan on all APs to gather the SNRs for all connected clients, and stuff the results into a database so i can see a graph of the SNR for any 1 client, or for the Average of the AP.

This helps a lot in these kind of cases, because you can see when it started to drop off.

The Classic case is where a Tree grows in front of some CPE - you can see the SNR gradually reducing.

I keep meaning to write the software to email me when a CPE or AP Average SNR starts dropping … but haven’t yet.

5
  • I run an hourly SNMP scan on all APs to gather the SNRs for all connected clients, and stuff the results into a database so i can see a graph of the SNR for any 1 client, or for the Average of the AP

Can i ask how is this done

6

Can i ask how is this done

Sure !

if you enabke SNMP on your mkrotik APs, you can (currently) access the lists of connected clients with :-
.1.3.6.1.4.1.14988.1.1.1.2.1.1

and the associated SNR at :-
.1.3.6.1.4.1.14988.1.1.1.2.1.3

Personally i use a Ubiquti RouterStation to do this, but only because i have a few lying about.

7

I already changed antenna, no luck :frowning:
Already changed polarity V to H, no luck :frowning:

Is it possible if the RX Sensitivity in AP side was damaged ? So AP could not hear Client clearly. Please advice.

8

I have all of the AP’s SNMP enabled and clients, using dude to monitor but not sure how to follow your instructions to snmp scan?

9

not sure how to follow your instructions to snmp scan

Maybe anther new product is born !

SNR Ticker.

How about if it cost < $100 to implement (hardware and software) ?

Any takers ?

Product would be a UBNT RS board and some firmware to flash into it.

10

Can you attach a screen shot of SNMP scan, and what other functions can it do?

11

Try ROSInfo - I have made some internal changes into the product for my own needs, however the product does exactly what you are looking for.

http://forum.mikrotik.com/t/rosinfo-router-monitoring/10122/1

Marcel

12

Doh ! looks like the Wheel was already invented …

13

Is that only for linux or can it used in windows?

14

REQUIREMENTS:

  • Linux
  • Apache
  • PHP5 with support for snmp
  • RRDTool 1.2
  • php-rrdtool (not mandatory)
  • SNMP utilities
  • Cron or another scheduling daemon
15

It is disheartening that this thread turned into something other than the problem at hand.

I already changed antenna, no luck
Already changed polarity V to H, no luck

Is it possible if the RX Sensitivity in AP side was damaged ? So AP could not hear Client clearly. Please advice.
I already changed antenna, no luck > :frowning:
Already changed polarity V to H, no luck > :frowning:

Is it possible if the RX Sensitivity in AP side was damaged ? So AP could not hear Client clearly. Please advice.

Based upon your noise floor at the AP side I would be inclined to beleive that in fact you are correct that the receive amp may be deafened.

Try changing the radio card on the AP side.

16

Thanks tgrand for you reply. I really appreciate :slight_smile:
And yes, radio at AP side is broken.

17

We see this problem from time to time using Omni Antennas. So be aware this
can happen again. We see this only at some locations.