On 21 Mar, 2011, at 12:18 am, da...@lang.hm wrote: >> 0) Buffering more than 1 second of data is always unacceptable. > > what about satellite links? my understanding is that the four round trips to > geosync orbit (request up, down, reply up down) result in approximatly 1 sec > round trip.
That is true, but it doesn't require more than a full second of buffering, just lots of FEC to avoid packet loss on the link. At those timescales, you want the flow to look smooth, not bursty. Bursty is normal at 100ms timescales. What I've heard is that most consumer satellite links use split-TCP anyway (proxy boxes at each end) thus relieving the Internet at large from coping with an unusual problem. However, it also seems likely that backbone satellite links exist which do not use this technique. I heard something about South America, maybe? Anyway, with a 1-second RTT, the formula comes out to max 1 second of buffering because of the clamping. - Jonathan _______________________________________________ Bloat mailing list Bloat@lists.bufferbloat.net https://lists.bufferbloat.net/listinfo/bloat
