Slow connection issues and unstable latency or request timeout.

  • 2
  • Question
  • Updated 3 years ago
We have install 8 AP per floor and this building is a 4 stories building.
We have face slow connection issues and unstable latency issues or event request timeout.
Each AP is going to serve about less than 15 clients with uncontrolled traffic, mean they can do what they want including downloading p2p or torrent. But each clients is limited to 0.8Mbps download and upload speed.
Sometimes the clients can get about 0.7++Mbp but sometimes less than 0.1Mbps speed.
May i know what is the problem?
Here is the channel graph that i scan using mobile phone.
Is it AP place too closed and adjust too much power causing self interference?
Based on this graph, it is i am having self interference?


Photo of Nelson Chai

Nelson Chai

  • 7 Posts
  • 0 Reply Likes

Posted 3 years ago

  • 2
Photo of Primož Marinšek

Primož Marinšek, AlphaDog

  • 413 Posts
  • 48 Reply Likes
What you've got here is a very bad channel plan with way too many APs set to complitely wrong channels.

You've got masive adjacent channel interference and Co channel contention. I'm guessing that the speed difference you are experiencing is caused by the hidden-node problem that is causing retransmittions and probably packet drops.

At every location you did the screen shot you've got 8 other APs and many clients that are interfering with where you are happen to be standing.

If you want your network to work, you would really need to redisign it, but for starters unplug every other AP and see if it helps. I'm about 95% certain it will.
Photo of Primož Marinšek

Primož Marinšek, AlphaDog

  • 413 Posts
  • 48 Reply Likes
Another suggestion I have is to moove APs from the hallway into the rooms and let the wall help with attenuation.
Photo of Mat Murdock

Mat Murdock

  • 9 Posts
  • 0 Reply Likes
Move the AP's into rooms. Turn the power down. Use only channels 1,6,and 11. Try not to have AP's that are next to each other use the same channels. Make sure to utilize the 5 ghz band.

Mat
Photo of Koen

Koen

  • 30 Posts
  • 1 Reply Like
Another way to reduce co-channel interference is disabling the lower data rates. Also disable 802.11b rates if no 802.11b clients are present in your network, these clients really slow down your network. Configure your ZD as follows:

in cli

> enable
# config
# wlan "wlan-name"
# ofdm-only
# end
# end
# show wlan name "Wlan_name"

Also reduce the number of SSIDs configured on your access points to lower management traffic overhead (beacons).

The TX power of your access points should match the value of the max.TX power of your weakest client to avoid collisions at the access point.
Photo of Koen

Koen

  • 30 Posts
  • 1 Reply Like
Co-channel seperation should be idially 20dB seperation between access points on the same channel at the edge of the cell. ex. AP01: -65dBm at edge of the cell & AP02 -85dBm at that same location.