4 BLUE
Use average header to manage congest to differ with RED, BLUE uses the incident that lose a bag and link leisure incident to manage congest congest. BLUE kept bag of mark of in order to of Pm of a probability. If because alignment spills over,be brought about,last lose a bag, BLUE increases Pm, increased Xiang Yuanduan to send the rate that congest informs consequently. Contrary, if cause alignment sky as a result of link leisure, BLUE reduces Pm. Such BLUE send congest to inform information ground of speed with respect to effectively control. Its are specific and algorithmic following place show:
Upon Link Idle Event:
If ((now-last_update)>freeze_time)
Pm = Pm-d2;
Last_update = Now;
Upon Packet Loss Event:
If ((now-last_updatte)>freeze_time)
Pm = Pm D1;
Last_update = Now;
BLUE landlord wants parameter to have D1, D2 and Freeze_time. Among them, d1 decided the amount that increases when the Pm when alignment spills over, d2 decided when link is disengaged Pm reductive is measured. Freeze_time decided to change Pm continuously most the interval between Xiaoshi, make before after Pm is changed, changing again action of can effective play. Generally speaking, d1 should compare D2 a lot of bigger, because become,this basically is congest government is too conservative (Conservative) or too radical (Aggressive) when, can cause link utilization rate very low; And lose a bag to happen in congest only when government is too conservative. Such, lose the proportion with packet of larger incident through gifting, BLUE can increase quickly to make response immediately in great quantities to discharge.
BLUE most earth contribution depends on, use relatively lesser buffer to be able to finish congest control. Such, BLUE decreased to carry upright defer, increased the handling capacity that TCP sheds. Additional, lesser buffer demand also makes road by implement more free spaces will carry out other ways by implement function, the way with for instance older memory by the watch, raised a way thereby by implement function. And should achieve similar result, RED needs a lot of bigger buffer.
BLUE is based on the congest management of the incident that lose a bag and link leisure incident, can better land estimates congest rate, make proper response thereby. Ratio of ground of its mark bag is accordingly relative stabler, this makes captain relatively stable also again, reduced defer to shake. And RED is based on management of congest of average header ground, because cannot estimate congest seriousness in time, be in especially load is very heavy, below the circumstance with very sharp change, often bring about captain wave motion is very big. Increased to lose packet of number and defer to shake, produce global synchronism phenomenon even, lower link utilization rate.
BLUE of 4.1 random fairness (Stochastic Fair BLUE, SFB)
Now, more and more application do not use the congest of TCP to control a mechanism, these shedding can flow to suiting bring very earth influence, make when competitive bandwidth they are immersed in " hungry " even. Because this must flow to suiting,undertake protective.
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