4 ms·
Can you explain what BBR is? Thank you.
by notaplumber 8y ago
Can you explain what BBR is? Thank you.
- loeg 8y agoTCP congestion control algorithm: https://tools.ietf.org/html/draft-cardwell-iccrg-bbr-congestion-control-00 https://tools.ietf.org/html/draft-cardwell-iccrg-bbr-congest...
- ggm 8y agoSorry, good point. its a modification to how TCP backs off under loss, and then re-approaches the prior rate. Traditional TCP does an exponential back-off and recovery model. This takes a long time to get back to the fastest achieved rate. Its a very jaggy sawtooth. BBR gets back to the prior rate faster. BBR is a very fast recovery algorithm. Its not always very "fair" to other forms of TCP. BSD and Linux both have kernels which allow selection of different methods of backoff. BSD has cubic, and some other choices, at this point only Linux appears to have the BBR method integrated. It is in test in the BSD stack (I believe) If you have sole use of a host, and want to do long-distance file transfer, with loss, BBR can sometimes get you things faster. If you're in a Data Center (DC) BBR can cope really well with dumb switch packetloss, getting you significantly faster recovery.