Bufferbloat is all wet? Bufferbloat is all wet? Stephen Hemminger - - PowerPoint PPT Presentation
Bufferbloat is all wet? Bufferbloat is all wet? Stephen Hemminger Stephen Hemminger s t e p h e n @n e t w o r k p l u mb e r . o r g s t e p h e n @n e t w o r k p l u mb e r . o r g @n e t w
Stephen Hemminger Stephen Hemminger s t e p h e n @n e t w
k s t e p h e n @n e t w
k p l u mb e r .
g p l u mb e r .
g @n e t w
k p l u mb e r @n e t w
k p l u mb e r
Linuxcon Europe Oct 2014
– D
e mo n s t r a t i
D e mo n s t r a t i
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h e G
T h e G
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h e B a d T h e B a d
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h e U g l y T h e U g l y
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h r
g h p u t T h r
g h p u t
n l
d 1 %
a d v e r t i s e d D
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a d v e r t i s e d
p l
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k U p l
d d
s n ' t w
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a t e n c y L a t e n c y
a r g e ( > 2 ms ) l a r g e ( > 2 ms )
a r i a b l e V a r i a b l e
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n d n
a c k e t l
s ! ! ! A n d n
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av e ragetim einque ue= utilization se rv icerate 1− utilization
Graphic courtesy Sprint, Apricot 2004
From Fred Baker: Bufferbloat!
T h r
g h p u t M b i t s / s e c L a t e n c y R
n d T r i p T i me F a i r n e s s
Increasing Measurable Throughput Increasing TCP Window “knee” “cliff” Bottleneck Capacity Queue Depth
m e anthroughput= e ffe ctivewindow m e anroundtriptim e
From Fred Baker: Bufferbloat!
– M
a x i mu m w i n d
6 4 k M a x i mu m w i n d
6 4 k
– B
a n d w i d t h l i mi t t
mb i t s B a n d w i d t h l i mi t t
mb i t s
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e c e i v e w i n d
l i mi t e d R e c e i v e w i n d
l i mi t e d
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y t e s / s e c B y t e s / s e c
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a c k e s / s e c P a c k e s / s e c
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a t e n c y L a t e n c y
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e t p e r f N e t p e r f
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n l
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p l
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a t e n c y me a s u r e me n t L a t e n c y me a s u r e me n t
Høiland-Jørgensen T., Battling Bufgerbloat
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Høiland-Jørgensen T., Battling Bufgerbloat
Høiland-Jørgensen T., Battling Bufgerbloat
Høiland-Jørgensen T., Battling Bufgerbloat
Router
Backbone ISP ISP Sender Receiver Application Application TCP QDisc TCP Router
u e u i n g d i s c i p l i n e s Q u e u i n g d i s c i p l i n e s
–
C
e l , P I E , . . . C
e l , P I E , . . .
i n u x i n t e r n a l L i n u x i n t e r n a l
–
B Q L , F Q , P a c i n g B Q L , F Q , P a c i n g
e f a u l t q d i s c D e f a u l t q d i s c
Sysctl -w sys.net.core.default_qdisc=fq_codel Sysctl -w sys.net.core.default_qdisc=fq_codel
Y e s , ma n y t i me s
e r Y e s , ma n y t i me s
e r
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u s
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a b u g i t ' s a f e a t u r e ?
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r
l e m i s p
i t i c a l n
t e c h n i c a l P r
l e m i s p
i t i c a l n
t e c h n i c a l
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g g r e g a t i
A g g r e g a t i
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u l t i c a s t M u l t i c a s t
– P
r
r i e t a r y fi r mw a r e P r
r i e t a r y fi r mw a r e
Dave T<dave.taht@bufferbloat.net>
Bufferbloat.net: http://bufferbloat.net Email Lists: http://lists.bufferbloat.net IRC Channel: #bufferbloat on chat.freenode.net CeroWrt: http://www.bufferbloat.net/projects/cerowrt Other talks: http://mirrors.bufferbloat.net/Talks Jim Gettys Blog – http://gettys.wordpress.com RRUL Test- https://github.com/tohojo/netperf-wrapper
A big thanks to the bloat mailing list, Jim, Kathie, Van, and Eric, ISC, the CeroWrt contributors, OpenWrt, the Internet Civil Engineering
Institute, and the Google Fiber for their interest and support in the work!