Symptoms of bufferbloat-induced congestion

Once a network is congested, various service protocols (statistically insignificant in terms of additional network load, but mission-critical) can’t do their jobs. Here are some examples

  • DNS - adding hundreds of ms of latencies to turning a website into an IP address is not good. With a typical web page doing dozens, even hundreds of DNS lookups, DNS not getting through in a timely fashion results in vastly slower browsing.
  • NTP - the network time protocol - relies on somewhat timely delivery of packets in order to keep your computer’s clock accurate. Lots of things rely on accurate timekeeping.
  • ARP - the address resolution protocol - also relies on timely resolution in order to even find other devices on your network.
  • DHCP - if these packets are lost or excessively delayed, machines can’t get on the network in the first place.
  • Routing - many routing protocols depend on packet drops as a way of monitoring network health and are time sensitive.
  • VOIP - needs about a single packet per 10ms flow in order to be good, and less than 30ms jitter.
  • Gamers will get fragged a lot more often with latencies above their twitch factor.
  • IPv6 relies on even more specialized packet types for autoconfiguration, e.g. the equivalent of ARP
  • Encapsulated packets (VPNs, X11 over ssh, IPv6 over 6rd/6to4) also suffer.
To edit this page, submit a pull request to the Github repository.
RSS feed

Recent News & Articles

Dec 30, 2020 Wiki page
Tests for Bufferbloat
Oct 5, 2020 Wiki page
Oct 5, 2020 Wiki page
Oct 5, 2020 Wiki page
Mar 5, 2020 Wiki page
What Can I Do About Bufferbloat?

Find us elsewhere

Bufferbloat Mailing Lists
#bufferbloat on Twitter
Google+ group
Archived Bufferbloat pages from the Wayback Machine


Comcast Research Innovation Fund
Nlnet Foundation
Shuttleworth Foundation

Bufferbloat Related Projects

OpenWrt Project
Congestion Control Blog
Flent Network Test Suite
The Cake shaper
CeroWrt (where it all started)

Network Performance Related Resources

Jim Gettys' Blog - The chairman of the Fjord
Toke's Blog - Karlstad University's work on bloat
Voip Users Conference - Weekly Videoconference mostly about voip
Candelatech - A wifi testing company that "gets it".