PHY Error Stats

[jitendra_jari]

Can anyone tells how to read and understand this logs and what it indicate ?

------------ PHY Error Stats ------------

1570295586 PHY errors since clearing all stats

    298 OFDM timing

    18 OFDM illegal parity

    4 OFDM illegal rate

    187 OFDM illegal service

    19 OFDM restart              

    873 CCK timing

    3 CCK header crc

    192 CCK illegal rate

    86 CCK restart

    2932 zero len crc

    403750321 phy ofdm group

    1166540653 phy cck group

1087 PHY errors since clearing delta stats (1 sec)

    52 OFDM timing

    1 OFDM illegal parity

    124 OFDM illegal service

    12 OFDM restart

    283 CCK timing

    50 CCK illegal rate

    10 CCK restart

    555 zero len crc

Histogram of PHY errors per second (pcttime in each range)

   0  1-500 ..1K  ..2K  ..5K ..10K ..20K ..50K .100K  more

   0    13    34    24    28     0     0     0     0     0

 

[roberto_flores_]

Hello Jitendra,

This is a section in the support info file either under 'Athstats Radio 0' or 'Athstats Radio 1' (Radio 0 is 2.4G and Radio 1 is 5G).  These are error counters and statistics in the phy layer or over the air errors that affect the tx/rx of the packet(s).  The summary or the most important thing you want to be able to analyze is the Histogram of PHY errors per second.  In this case:
0  1-500 ..1K  ..2K  ..5K ..10K ..20K ..50K .100K  more
0    13       34    24    28     0       0       0        0       0

This reads x% of the time (bottom #), the AP has yK errors (top #).  Let's take for example the 28.
28% of the time (since last reboot), the AP has seen between 2,000 and 5,000 errors.

For reference, 10% at 10K or above is recommended to be analyzed further by opening a case with Ruckus tech support.  In this instance, interference is somewhat affecting your AP but not enough to affect/degrade performance of data or voice.  Packet errors lead to re-transmissions which slows down AP/client communication and the medium.

If you see large % of time values at 20K or above, the next thing that will need to be analyzed are the clients under the radio WLANs.  The clients' PER or packet error rates tell us the error rate for a client in a particular WLAN/SSID.  If you see clients under section 'Wlan info', in support info file, and they are all suffering from interference, then perhaps an spectrum analysis at the location where the AP is might be in place to understand the air environment and perhaps manually assign a channel.

Thank you,

-Roberto Flores.
Ruckus Wireless Tech. Support Eng.

[Anusha_Vemula]

Hello Jitendra,

Adding to Roberto's info, histogram logs should be validated against the AP's uptime.

If there are large % of time values at 10k or above, then check the AP's uptime. If it shows as 2 days or less time, then we should consider that there is high amount of interference in the network.

If the uptime is more no.of days(like 10 days), then we can ignore the values till 10k or below. Again, if there is large % of time values at 20k and above if APs uptime is more than 2 days, then we will consider them.

If there is high interference, you will observe throughput issues, client connectivity issues and roaming issues in the network.

It is always suggested to open a ticket with Ruckus support and we will assist you further based on the logs and AP deployment (overlap coverage area).

We recommend to do periodic site surveys in these kind of deployments.

- Anusha

[jitendra_jari]

Thanks for good explanation.

To continue above discussion, clients are not authorized or it may be not connected to AP with distance 300 m and clear LoS .What are possible causes and how can overcome this issue?

Even  i replace AP but same issue faced.

Radio 802.11b/g

Current Channel                     10

WLAN Group                       Default

Background Scanning         Enabled

TX Power                           100%         

# of Client Devices               0%

Retries/% Drops             1.88 / 0.00%

Non-unicast                        0.0357

Packets/Bytes Received          111K/13M

Packets/Bytes Transmitted     29K/4.0M

Noise Floor                               -96  

PHY Errors                                 1160

% AirTime (total/busy/RX/TX)  69.1/54.2/15.0/0.0     

AP Uptime  1d 20h 39m