UpdateonTCPAlterna0veBackoffwithECN(ABE)
dra=-khademi-alterna0vebackoff-ecn
NaeemKhademi,MichaelWelzl,
GrenvilleArmitageandGorryFairhurst
TCPMWG-IETF94,Yokohama–5November2015
I-D’sScope
•  AnexperimentalupdatetoRFC3168:updatestheTCPsender-side
reacMontoacongesMonnoMficaMonreceivedviaECN
•  RFC3168Sec0on6.1.2:
“IfthesenderreceivesanECN-Echo(ECE)ACKpacket…theindicaMonof
congesMonshouldbetreatedjustasaconges0onlossinnon-ECN-Capable
TCP.Thatis,theTCPsourcehalvesthecongesMonwindowcwndandreduces
theslowstartthresholdssthresh.”
•  UpdatetoRFC3168Sec0on6.1.2:
“IfthesenderreceivesanECN-Echo(ECE)ACKpacket…theindicaMonof
congesMonSHOULDinducealessconserva0vereac0onthanloss:theTCP
sourcemulMpliesthecongesMonwindowcwndwith0.8andreducestheslow
startthresholdssthresh.”
2
StatusoftheI-D
•  DiscussionsontheTCPMML(uptoIETFPrague):
–  AddressedMarkAllman’scommentswithregardstobetaecnasapercentage
–  ReviewfromAnilAgarwalisresponded
•  DiscussionsontheICCRGML(a=erIETFPrague):
–  RespondedtocommentsfromMichaelScharfandBobBriscoe
•  SubmiXed-01:
–  Someeditorialwork,moreelaboraMvetextontheraMonalebehindABEin
IntroducMon(SecMon1)andDiscussion(SecMon2)
–  Discussion(SecMon2)explains:
•  whereABEcanbeuseful(lightlymulMplexed,high-BDPaccesslinks)
•  ABEisprac,calratherthanideal(staMcbetaratherthananadapMveone)
•  ThechoiceofmulMplier(nochangetobetaloss)
–  should->SHOULDintheupdateofRFC3168(SecMon3)
–  Theproposedupdateis“experimental”ratherthanstandard-track
3
Q&A
4