4 ms·

I wonder what the real-world impact of this regression is as I'm sure there are plenty of IOT devices out there that are running the affected Linux versions. As

by r1ch 8y ago

I wonder what the real-world impact of this regression is as I'm sure there are plenty of IOT devices out there that are running the affected Linux versions. As the issue likely only manifests at higher bandwidths, I guess things like wireless IP cameras or Wifi attached NAS would be the most affected.

Const-me 8y ago
WiFi cameras don’t send that much data, WiFi quality varies based on distance to AP and radio interference. Also WiFi is often slower. A camera that streams 50 mbit/sec or more would be completely broken on any 802.11g 54 mbit/sec network. NAS-es are better example; they are often bandwidth bound. My guess is, users are typically connecting them with a cable. Most clients are wireless these days (e.g. I happen to type this on a wifi connected laptop), so doing 2 radio hops, NAS-router and router-client, isn’t good for performance: both data streams are competing for the same radio frequencies.
- jws 8y ago
  The afflicted Linux devices will be spoiling the commons, even if they can still get their own data sent without stalling. Instead of combining frames for more efficient use of the available wireless channel they will be sending an individual frame per packet and degrading the total useful capacity of the channel. Wikipedia asserts in its WiFi frame aggregation article that the overhead of a packet can be greater than the actual data of the packet on high speed WiFi.
  - wtallis 8y ago
    The afflicted devices definitely make much worse usage of their airtime, but do they actually end up getting much more total airtime/TXOPs? The stations in question are definitely their own worst victim, and the impact they have on competing stations could be far smaller.
danmg 8y ago
Most IOT things aren't high bandwith. They're low latency if anything. So this regression wasn't bad for them.

4 ms·

I wonder what the real-world impact of this regression is as I'm sure there are plenty of IOT devices out there that are running the affected Linux versions. As

by r1ch 8y ago

Const-me 8y ago
WiFi cameras don’t send that much data, WiFi quality varies based on distance to AP and radio interference. Also WiFi is often slower. A camera that streams 50 mbit/sec or more would be completely broken on any 802.11g 54 mbit/sec network. NAS-es are better example; they are often bandwidth bound. My guess is, users are typically connecting them with a cable. Most clients are wireless these days (e.g. I happen to type this on a wifi connected laptop), so doing 2 radio hops, NAS-router and router-client, isn’t good for performance: both data streams are competing for the same radio frequencies.
- jws 8y ago
  The afflicted Linux devices will be spoiling the commons, even if they can still get their own data sent without stalling. Instead of combining frames for more efficient use of the available wireless channel they will be sending an individual frame per packet and degrading the total useful capacity of the channel. Wikipedia asserts in its WiFi frame aggregation article that the overhead of a packet can be greater than the actual data of the packet on high speed WiFi.
  - wtallis 8y ago
    The afflicted devices definitely make much worse usage of their airtime, but do they actually end up getting much more total airtime/TXOPs? The stations in question are definitely their own worst victim, and the impact they have on competing stations could be far smaller.
danmg 8y ago
Most IOT things aren't high bandwith. They're low latency if anything. So this regression wasn't bad for them.