3 ms·
On a somewhat related note, there are some channels on 802.11ac that are designated as "DFS" (dynamic frequency switching) channels, because they are sharing fr
by Dwedit 3y ago
On a somewhat related note, there are some channels on 802.11ac that are designated as "DFS" (dynamic frequency switching) channels, because they are sharing frequency ranges with weather radar equipment. Networking equipment will periodically monitor for radar signals. I think I heard somewhere that this monitoring for radar signals will temporarily add extra latency to the connection during this time. If any equipment detects a radar signal, it ends the wifi network and switches to another channel. But if another DFS channel is chosen at this time, there is a 60 second timeout before the new channel is confirmed.
So if you're trying to avoid latency spikes, don't use DFS channels on 802.11ac.
Page here has a list of all the Wifi channels on 5GHz: https://www.networkcomputing.com/wireless-infrastructure/channel-bonding-wifi-rules-and-regulations https://www.networkcomputing.com/wireless-infrastructure/cha...
In particular, you can't get a 160Mhz wide channel (8 channels bonded together) on 802.11ac without being on a DFS channel.
- dtaht 3y agoIn general, using an empty channel, less wide, has more range, and with less interference So I would vastly prefer that in contended scenarios - an apartment building for example - that the actual channel width provisioned to be not be much more than what the ISP is providing. (and that the wifi be de-bufferbloated: https://lwn.net/Articles/705884/ https://lwn.net/Articles/705884/ ) Instead people keep provisioning 160mhz channels with dozens of other APs also living on those channels, and interference and retries go way up... Above 50Mbits, most of the bufferbloat problem shifts to the wifi.
- Dwedit 3y agoSome people have LAN traffic. Not all Wifi is Internet.
- jonatron 3y agoI remember having problems with Meraki Access Points where if you set the channel to auto, it'd choose a DFS channel, then within a day all of them would be on the same non-DFS channel. Manually setting each AP to different non-DFS channels helped but eventually they were replaced with better non-Meraki APs.