4 ms·

Shouldn't RED type algorithms in routers prevent buffer bloat?

• jorangreef 11y ago
  It may help for other users on the LAN but it's going to be years before it's fully deployed. It's not the solution for today. In any event, I don't think it's going to make any inroads towards fixing bufferbloat for a single user on the same machine, i.e. where multiple applications are creating several seconds of bufferbloat each, the latency sensitive applications (Skype, Google searches, typical web browsing) are still all going to suffer. I think it's actually not a router issue but an application issue, in the same sense that CPU overusage by one application is an application issue. Applications just need to be better designed to not bloat a user's network. Hopefully, the next major Apple OS update will include bufferbloat measurements in Activity Monitor, so offending apps can be named and shamed. But even this won't prevent web apps from having massive bufferbloat footprints (for that the browsers will need to share data with Activity Monitor, or highlight this to the user). After this, I think pressure from users on application developers to reduce bufferbloat footprint and build network efficient apps is the way forward. Then we will be able to switch to some of the better higher-bandwidth TCP congestion avoidance algorithms without having to settle for algorithms which ignore latency as a congestion signal (packet loss is a poor signal and causes throughput to saw-tooth).
  • stplsd 11y ago
    Maybe I misunderstood your first message about 'buffer bloat'. I was thinking about buffer bloat in routers/switches when many TCP connection start to send packet, router starts to buffer them, once packets are dropped, congestion avoidance in TCP connections is activated and synchronises - bandwidth goes down and once again increases in all TCP connections, and this cycle (more packets are sent/packet drops/congestion avoidance triggered) repeats again.
    • jorangreef 11y ago
      Yes that's right. I meant the same. Each application on a user's machine contributes to bufferbloat generated by that machine, and bufferbloat as a whole encountered at the router (which affects everyone on the LAN).
    • noselasd 11y ago
      Note that bufferbloat is a problem regardless of there being many or few TCP connections.
• motoboi 11y ago
  The Codel paper explains why not (Codel creator is the same as RED). RED needs fine tuning and people couldn't do it right. Codel has only one knob with a sensible default. This should simplify implementation and allow widespread adoption.