Fluctuating Ping

[adam_carter_607]

I have deployed a Zonedirector 1100 and 6 x zf7372 APs. The APs are connected to the same PoE switch as the ZoneDirector.

APs are not configured for mesh mode.

Signal coverage is good, but I am getting fluctuating pings when testing from various devices - it follows the pattern 1 good ping (1ms), 1 average pint (~100ms), then one higher ping (200-300ms) - then repeat.

For testing I am pinging the IP address of the ZoneDirector to eliminate any other network issues. Checking the logs it shows the channel selection and client association to be static - I am not moving around but in a fixed position and the ZD reports this to be accurate:

Reply from 10.10.1.20: bytes=32 time=2ms TTL=64
Reply from 10.10.1.20: bytes=32 time=10ms TTL=64
Reply from 10.10.1.20: bytes=32 time=211ms TTL=64
Reply from 10.10.1.20: bytes=32 time=136ms TTL=64
Reply from 10.10.1.20: bytes=32 time<1ms TTL=64
Reply from 10.10.1.20: bytes=32 time=2ms TTL=64
Reply from 10.10.1.20: bytes=32 time=133ms TTL=64
Reply from 10.10.1.20: bytes=32 time=10ms TTL=64
Reply from 10.10.1.20: bytes=32 time=249ms TTL=64
Reply from 10.10.1.20: bytes=32 time=2ms TTL=64

I have tested on both 2.4GHz and 5GHz channels but I get the same result.
The pings never drop and I get good throughput when transferring data, but I am not sure the latency should fluctuate as much as this.

Firmware on ZD is the latest ( 9.6.1.0 build 15)
Does anyone have any ideas?

Thanks

[adam_carter_607]

It does look like interference - have you done a wireless scan to see if there is anything else broadcasting on the same (or close) channel?
If not is there anything else that could be transmitting on a similar frequency or generating a lot of noise (think microwave,cordless phones, electrical motors).
Also try moving the AP to a new location to rule out environmental factors

[greg_morgan_610]

Hi Adam,

I think I've found the problem. I'm using InSSIDer to monitor coverage and interference from other AP's. I've realised that when this application is open, my pings sky-rocket. This makes sense because the application obviously also sends pings to the AP to provide real-time RSL levels.

[greg_morgan_610]

Hi Adam,

I think I've found the problem. I'm using InSSIDer to monitor coverage and interference from other AP's. I've realised that when this application is open, my pings sky-rocket. This makes sense because the application obviously also sends pings to the AP to provide real-time RSL levels.

[adam_carter_607]

Ah - you probably shouldn't be scanning and testing throughput on the same wireless interface at the same time 😉

[greg_morgan_610]

You learn something new everyday... Well thanks for all your help guys.