Forums1000 <[email protected]> asked > Curiously, there is little information to be found regarding bufferbloat > and UDP. > > I did find hints briefly alluding to some problems: > > 1)With UDP, you cannot uniquely identify a flow? This prevents an > AQM-algorithm to drop packets for an (several) offending UDP flow(s). > > 2) Unlike TCP, UDP does not back down when encountering packet loss > > So how does UDP fit in concerning efforts to combat bufferbloat? Having one > queue to mange all UDP 'flows' does not seem like a good approach. > > Thanks for shining a light on this:-) > > Jeroen
Bufferbloat, or more correctly the lack of congestion control in UDP, is a problem for the designers of individual UDP-using programs. The behaviour of the program during congestion is a problem for everyone else (;-)) To oversimplify, - If the UDP programs is small-data punt and hope, no-one needs care. Very few such programs exist. - if the UDP programs is a stop-and-wait one like TFTP, it will be a self-limiting load on the net, and can be throttled by drops. This is similar to... -- if the program is self-limiting, such as VOIP or video, we really should be prepared to signal congestion to it using AQM or drops, but I don't know if anyone is doing such using UDP. Someone else on the list will know. - if the program uses resends, it will survive congestion control by drops, and if the program is very heavily used, we may need to provide congestion control for it, or we'll get "bloated". If everyone in the world suddenly switched to UDP for web pages, we'd need to identify such TCP-like streams and throttle them via packet drops, to avoid congestive collapse. - if the UDP program is large-data punt-and-hope, it would be both randomly unreliable and harmful to the net. In that case, I think we might need to hunt down the author and suggest something, quick before he goes out of business for bringing down the net. --dave -- David Collier-Brown, | Always do right. This will gratify System Programmer and Author | some people and astonish the rest [email protected] | -- Mark Twain _______________________________________________ Bloat mailing list [email protected] https://lists.bufferbloat.net/listinfo/bloat
