SlideShare una empresa de Scribd logo

Lecture 4: TCP and TFRC

•
•
Wei Tsang Ooi
Wei Tsang Ooi
EducaciónTecnología
1 de 72
Descargar para leer sin conexión
TCP" Reno, NewReno, SACK 4 September 2009 CS5229, Semester 1, 2009/10 1
TCP Reno 4 September 2009 CS5229, Semester 1, 2009/10 2
14 cwnd ssthresh 12 10 8 6 4 2 0 4 September 2009 CS5229, Semester 1, 2009/10 3
new ack:" if (cwnd < sstresh)" cwnd += 1" else" cwnd += 1/cwnd 4 September 2009 CS5229, Semester 1, 2009/10 5
timeout:" retransmit 1st unacked" ssthresh = cwnd/2" cwnd = 1" 4 September 2009 CS5229, Semester 1, 2009/10 6
3rd duplicate ACK:" fast retransmission" (ie, retransmit 1st unack) " fast recovery" (details today)" ssthresh = cwnd = cwnd/2 4 September 2009 CS5229, Semester 1, 2009/10 7
TCP’s rule" send more packets if " L + cwnd > H" [ L .. H-1 ] are outstanding packets 4 September 2009 CS5229, Semester 1, 2009/10 10
4 September 2009 CS5229, Semester 1, 2009/10 11
Data Packets ACK Packets (received up to this seq number) Congestion Window Sequence Number Time 4 September 2009 CS5229, Semester 1, 2009/10 12
3rd dup ack:" retransmit 1st unacked" ssthresh = cwnd/2" cwnd = cwnd/2 4 September 2009 CS5229, Semester 1, 2009/10 13
Incorrectly clamping the congestion window too soon (without fast recovery) X 4 September 2009 CS5229, Semester 1, 2009/10 14
fast recovery:" keep the pipe occupied" 4 September 2009 CS5229, Semester 1, 2009/10 15
X 4 September 2009 CS5229, Semester 1, 2009/10 16
4 September 2009 CS5229, Semester 1, 2009/10 17
X X 4 September 2009 CS5229, Semester 1, 2009/10 18
TCP Reno timeout with multiple losses in a window 4 September 2009 CS5229, Semester 1, 2009/10 19
TCP NewReno 4 September 2009 CS5229, Semester 1, 2009/10 20
X X 4 September 2009 CS5229, Semester 1, 2009/10 21
4 September 2009 CS5229, Semester 1, 2009/10 22
3rd dup ack:" retransmit 1st unacked" ssthresh = cwnd/2" cwnd = cwnd/2 + 3" remember highest 4 September 2009 CS5229, Semester 1, 2009/10 25
“complete” ack:" (all are acked) " cwnd = ssthresh 4 September 2009 CS5229, Semester 1, 2009/10 26
“partial” ack:" (acknowledge n packets)" retransmit" cwnd = cwnd - n + 1 4 September 2009 CS5229, Semester 1, 2009/10 27
Note: RFC2581/RFC2582 give the accurate/gory details. Simplified version is presented here (eg. cwnd vs FlightSize, update of cwnd upon partial ACK). 4 September 2009 CS5229, Semester 1, 2009/10 29
What does a dup ACK tell us? 4 September 2009 CS5229, Semester 1, 2009/10 30
“Coarse Feedback” 4 September 2009 CS5229, Semester 1, 2009/10 31
TCP SACK 4 September 2009 CS5229, Semester 1, 2009/10 32
Use TCP header options to report received segments. 4 September 2009 CS5229, Semester 1, 2009/10 33
SACK Blocks:" 1st block - report most recently received segments" subsequent blocks - repeat most recent previous blocks 4 September 2009 CS5229, Semester 1, 2009/10 34
pipe: num of outstanding packets in the pipe." send only if pipe < cwnd 4 September 2009 CS5229, Semester 1, 2009/10 35
scoreboard: which packets have been received? 4 September 2009 CS5229, Semester 1, 2009/10 36
X X 4 September 2009 CS5229, Semester 1, 2009/10 37
3rd dup ack:" pipe = cwnd - 3" retransmit 1st unacked" ssthresh = cwnd/2" cwnd = cwnd/2 + 3 4 September 2009 CS5229, Semester 1, 2009/10 38
subsequent dup ack:" cwnd++" pipe--" if pipe < cwnd" send packet, pipe++ 4 September 2009 CS5229, Semester 1, 2009/10 39
“partial” ack:" retransmit" cwnd = cwnd - n + 1" pipe -= 2" if pipe < cwnd" send packet, pipe++ 4 September 2009 CS5229, Semester 1, 2009/10 40
Idea of SACK:" Which packet has left the network?" Where is the gap?" Decouple when to send and what to send. 4 September 2009 CS5229, Semester 1, 2009/10 43
TCP SACK recovers faster than NewReno with multiple losses in a window. 4 September 2009 CS5229, Semester 1, 2009/10 44
Deployment 4 September 2009 CS5229, Semester 1, 2009/10 57
Feb 2004 NewReno Reno 8% Tahoe 15% 77% 4 September 2009 CS5229, Semester 1, 2009/10 58
70% " SACK capable 4 September 2009 CS5229, Semester 1, 2009/10 59
TCP BIC/CUBIC" Linux 2.6.x 4 September 2009 CS5229, Semester 1, 2009/10 63
Compound TCP " MS Windows Vista 4 September 2009 CS5229, Semester 1, 2009/10 64
TFRC" equation-based" congestion control 4 September 2009 CS5229, Semester 1, 2009/10 65
Not everyone uses TCP 4 September 2009 CS5229, Semester 1, 2009/10 66
UDP:" Media streaming" Gaming" VoIP 4 September 2009 CS5229, Semester 1, 2009/10 67
Why not congestion controlled?" 1. UDP has low delay, no need full reliability. UDP " is not congestion controlled. 4 September 2009 CS5229, Semester 1, 2009/10 68
Why not congestion controlled?" 2. No incentive. OTOH, there are incentives NOT to use congestion control. 4 September 2009 CS5229, Semester 1, 2009/10 69
Sally Floyd, h+p://www.icir.org/floyd/tcp_unfriendly.html  4 September 2009 CS5229, Semester 1, 2009/10 70
“Unresponsive Flows” 4 September 2009 CS5229, Semester 1, 2009/10 71
Bad: lead to unfairness and congestion collapse. 4 September 2009 CS5229, Semester 1, 2009/10 72
Unfairness: unresponsive flows consume more bandwidth than congestion controlled flows. 4 September 2009 CS5229, Semester 1, 2009/10 73
Congestion Collapse: wasting bandwidth by sending packets that will be dropped 4 September 2009 CS5229, Semester 1, 2009/10 77
Today: " a TCP-friendly" unreliable protocol 4 September 2009 CS5229, Semester 1, 2009/10 78
Idea: " send at a rate that a TCP flow would send 4 September 2009 CS5229, Semester 1, 2009/10 79
we can do the AIMD-thing" at the source, or 4 September 2009 CS5229, Semester 1, 2009/10 80
4 September 2009 CS5229, Semester 1, 2009/10 81
equation-based " congestion control 4 September 2009 CS5229, Semester 1, 2009/10 82
steady" fair" responsive 4 September 2009 CS5229, Semester 1, 2009/10 83
how to determine" RTT" tRTO" p 4 September 2009 CS5229, Semester 1, 2009/10 84
p is not packet loss rate" but " loss event rate 4 September 2009 CS5229, Semester 1, 2009/10 85
4 September 2009 CS5229, Semester 1, 2009/10 86
4 September 2009 CS5229, Semester 1, 2009/10 87
4 September 2009 CS5229, Semester 1, 2009/10 88
RTT can fluctuates 4 September 2009 CS5229, Semester 1, 2009/10 89
4 September 2009 CS5229, Semester 1, 2009/10 90
4 September 2009 CS5229, Semester 1, 2009/10 91
4 September 2009 CS5229, Semester 1, 2009/10 92
4 September 2009 CS5229, Semester 1, 2009/10 93
how to initialize? 4 September 2009 CS5229, Semester 1, 2009/10 94
slow start" (until loss occur)" Tnow = min(2Tprev, 2Trecv) 4 September 2009 CS5229, Semester 1, 2009/10 95
no loss history, how?" solve p given T, RTT 4 September 2009 CS5229, Semester 1, 2009/10 96
4 September 2009 CS5229, Semester 1, 2009/10 97
TFRC is now part of DCCP 4 September 2009 CS5229, Semester 1, 2009/10 98

Recomendados

Lecture 5: RED
Lecture 5: REDLecture 5: RED
Lecture 5: REDWei Tsang Ooi
 
Lecture 2: Congestion Control and Avoidance
Lecture 2: Congestion Control and AvoidanceLecture 2: Congestion Control and Avoidance
Lecture 2: Congestion Control and AvoidanceWei Tsang Ooi
 
Go Back N Arq1
Go Back N Arq1Go Back N Arq1
Go Back N Arq1guestb4ff06
 
Group B Ppt
Group B PptGroup B Ppt
Group B Pptguestb4ff06
 
Analysis of TCP variants
Analysis of TCP variantsAnalysis of TCP variants
Analysis of TCP variantsInstitute of Technology, Nirma University
 
TCP Westwood
TCP WestwoodTCP Westwood
TCP WestwoodGuillemCarles
 
Congestion control in tcp
Congestion control in tcpCongestion control in tcp
Congestion control in tcpsamarai_apoc
 
TCP congestion control
TCP congestion controlTCP congestion control
TCP congestion controlShubham Jain
 

Recomendados

Lecture 5: RED
Lecture 5: REDLecture 5: RED
Lecture 5: REDWei Tsang Ooi
 
Lecture 2: Congestion Control and Avoidance
Lecture 2: Congestion Control and AvoidanceLecture 2: Congestion Control and Avoidance
Lecture 2: Congestion Control and AvoidanceWei Tsang Ooi
 
Go Back N Arq1
Go Back N Arq1Go Back N Arq1
Go Back N Arq1guestb4ff06
 
Group B Ppt
Group B PptGroup B Ppt
Group B Pptguestb4ff06
 
Analysis of TCP variants
Analysis of TCP variantsAnalysis of TCP variants
Analysis of TCP variantsInstitute of Technology, Nirma University
 
TCP Westwood
TCP WestwoodTCP Westwood
TCP WestwoodGuillemCarles
 
Congestion control in tcp
Congestion control in tcpCongestion control in tcp
Congestion control in tcpsamarai_apoc
 
TCP congestion control
TCP congestion controlTCP congestion control
TCP congestion controlShubham Jain
 
Balls and-bins model app
Balls and-bins model appBalls and-bins model app
Balls and-bins model appdeawoo Kim
 
Research paper
Research paperResearch paper
Research paperSanchit Rathi
 
CS5229 Lecture 5: TCP and TRFC
CS5229 Lecture 5: TCP and TRFCCS5229 Lecture 5: TCP and TRFC
CS5229 Lecture 5: TCP and TRFCWei Tsang Ooi
 
Social and economical networks from (big-)data - Esteban Moro II
Social and economical networks from (big-)data - Esteban Moro IISocial and economical networks from (big-)data - Esteban Moro II
Social and economical networks from (big-)data - Esteban Moro IILake Como School of Advanced Studies
 
A tutorial in Connectome Analysis (3) - Marcus Kaiser
A tutorial in Connectome Analysis (3) - Marcus KaiserA tutorial in Connectome Analysis (3) - Marcus Kaiser
A tutorial in Connectome Analysis (3) - Marcus KaiserLake Como School of Advanced Studies
 
TCP protocol flow control
TCP protocol flow control TCP protocol flow control
TCP protocol flow control anuragjagetiya
 
Congetion Control.pptx
Congetion Control.pptxCongetion Control.pptx
Congetion Control.pptxNaveen Dubey
 
Transmission Control Protocol (TCP)
Transmission Control Protocol (TCP)Transmission Control Protocol (TCP)
Transmission Control Protocol (TCP)k33a
 
TCP- Transmission Control Protocol
TCP- Transmission Control Protocol TCP- Transmission Control Protocol
TCP- Transmission Control Protocol Akhil .B
 
TCP/IP(networking)
TCP/IP(networking)TCP/IP(networking)
TCP/IP(networking)welcometofacebook
 
Tcp Congestion Avoidance
Tcp Congestion AvoidanceTcp Congestion Avoidance
Tcp Congestion AvoidanceRam Dutt Shukla
 
TCP/IP Network ppt
TCP/IP Network pptTCP/IP Network ppt
TCP/IP Network pptextraganesh
 
Cubic
CubicCubic
Cubicdeawoo Kim
 
TCP Model
TCP ModelTCP Model
TCP Modelmanojkum22
 
Congestion control
Congestion controlCongestion control
Congestion controlKrishna Ranjan
 
wimax Ppt for seminar
wimax Ppt for seminarwimax Ppt for seminar
wimax Ppt for seminarPratik Anand
 
SIGMM Education Effort Presentation at Business Meeting
SIGMM Education Effort Presentation at Business MeetingSIGMM Education Effort Presentation at Business Meeting
SIGMM Education Effort Presentation at Business MeetingWei Tsang Ooi
 
CS2106 Tutorial 2
CS2106 Tutorial 2CS2106 Tutorial 2
CS2106 Tutorial 2Wei Tsang Ooi
 
The Computer Science behind YouTube
The Computer Science behind YouTubeThe Computer Science behind YouTube
The Computer Science behind YouTubeWei Tsang Ooi
 
CS4344 09/10 Lecture 10: Transport Protocol for Networked Games
CS4344 09/10 Lecture 10: Transport Protocol for Networked GamesCS4344 09/10 Lecture 10: Transport Protocol for Networked Games
CS4344 09/10 Lecture 10: Transport Protocol for Networked GamesWei Tsang Ooi
 
CS4344 09/10 Lecture 9: Characteristics of Networked Game Traffic
CS4344 09/10 Lecture 9: Characteristics of Networked Game TrafficCS4344 09/10 Lecture 9: Characteristics of Networked Game Traffic
CS4344 09/10 Lecture 9: Characteristics of Networked Game TrafficWei Tsang Ooi
 
CS4344 09/10 Lecture 8: Hybrid Architecture
CS4344 09/10 Lecture 8: Hybrid ArchitectureCS4344 09/10 Lecture 8: Hybrid Architecture
CS4344 09/10 Lecture 8: Hybrid ArchitectureWei Tsang Ooi
 

Más contenido relacionado

Destacado

Balls and-bins model app
Balls and-bins model appBalls and-bins model app
Balls and-bins model appdeawoo Kim
 
CS5229 Lecture 5: TCP and TRFC
CS5229 Lecture 5: TCP and TRFCCS5229 Lecture 5: TCP and TRFC
CS5229 Lecture 5: TCP and TRFCWei Tsang Ooi
 
TCP protocol flow control
TCP protocol flow control TCP protocol flow control
TCP protocol flow control anuragjagetiya
 
Congetion Control.pptx
Congetion Control.pptxCongetion Control.pptx
Congetion Control.pptxNaveen Dubey
 
Transmission Control Protocol (TCP)
Transmission Control Protocol (TCP)Transmission Control Protocol (TCP)
Transmission Control Protocol (TCP)k33a
 
TCP- Transmission Control Protocol
TCP- Transmission Control Protocol TCP- Transmission Control Protocol
TCP- Transmission Control Protocol Akhil .B
 
Tcp Congestion Avoidance
Tcp Congestion AvoidanceTcp Congestion Avoidance
Tcp Congestion AvoidanceRam Dutt Shukla
 
TCP/IP Network ppt
TCP/IP Network pptTCP/IP Network ppt
TCP/IP Network pptextraganesh
 
wimax Ppt for seminar
wimax Ppt for seminarwimax Ppt for seminar
wimax Ppt for seminarPratik Anand
 

Destacado (16)

Balls and-bins model app
Balls and-bins model appBalls and-bins model app
Balls and-bins model app
 
Research paper
Research paperResearch paper
Research paper
 
CS5229 Lecture 5: TCP and TRFC
CS5229 Lecture 5: TCP and TRFCCS5229 Lecture 5: TCP and TRFC
CS5229 Lecture 5: TCP and TRFC
 
Social and economical networks from (big-)data - Esteban Moro II
Social and economical networks from (big-)data - Esteban Moro IISocial and economical networks from (big-)data - Esteban Moro II
Social and economical networks from (big-)data - Esteban Moro II
 
A tutorial in Connectome Analysis (3) - Marcus Kaiser
A tutorial in Connectome Analysis (3) - Marcus KaiserA tutorial in Connectome Analysis (3) - Marcus Kaiser
A tutorial in Connectome Analysis (3) - Marcus Kaiser
 
TCP protocol flow control
TCP protocol flow control TCP protocol flow control
TCP protocol flow control
 
Congetion Control.pptx
Congetion Control.pptxCongetion Control.pptx
Congetion Control.pptx
 
Transmission Control Protocol (TCP)
Transmission Control Protocol (TCP)Transmission Control Protocol (TCP)
Transmission Control Protocol (TCP)
 
TCP- Transmission Control Protocol
TCP- Transmission Control Protocol TCP- Transmission Control Protocol
TCP- Transmission Control Protocol
 
TCP/IP(networking)
TCP/IP(networking)TCP/IP(networking)
TCP/IP(networking)
 
Tcp Congestion Avoidance
Tcp Congestion AvoidanceTcp Congestion Avoidance
Tcp Congestion Avoidance
 
TCP/IP Network ppt
TCP/IP Network pptTCP/IP Network ppt
TCP/IP Network ppt
 
Cubic
CubicCubic
Cubic
 
TCP Model
TCP ModelTCP Model
TCP Model
 
Congestion control
Congestion controlCongestion control
Congestion control
 
wimax Ppt for seminar
wimax Ppt for seminarwimax Ppt for seminar
wimax Ppt for seminar
 

Más de Wei Tsang Ooi

SIGMM Education Effort Presentation at Business Meeting
SIGMM Education Effort Presentation at Business MeetingSIGMM Education Effort Presentation at Business Meeting
SIGMM Education Effort Presentation at Business MeetingWei Tsang Ooi
 
The Computer Science behind YouTube
The Computer Science behind YouTubeThe Computer Science behind YouTube
The Computer Science behind YouTubeWei Tsang Ooi
 
CS4344 09/10 Lecture 10: Transport Protocol for Networked Games
CS4344 09/10 Lecture 10: Transport Protocol for Networked GamesCS4344 09/10 Lecture 10: Transport Protocol for Networked Games
CS4344 09/10 Lecture 10: Transport Protocol for Networked GamesWei Tsang Ooi
 
CS4344 09/10 Lecture 9: Characteristics of Networked Game Traffic
CS4344 09/10 Lecture 9: Characteristics of Networked Game TrafficCS4344 09/10 Lecture 9: Characteristics of Networked Game Traffic
CS4344 09/10 Lecture 9: Characteristics of Networked Game TrafficWei Tsang Ooi
 
CS4344 09/10 Lecture 8: Hybrid Architecture
CS4344 09/10 Lecture 8: Hybrid ArchitectureCS4344 09/10 Lecture 8: Hybrid Architecture
CS4344 09/10 Lecture 8: Hybrid ArchitectureWei Tsang Ooi
 
CS4344 09/10 Lecture 7: P2P Interest Management
CS4344 09/10 Lecture 7: P2P Interest ManagementCS4344 09/10 Lecture 7: P2P Interest Management
CS4344 09/10 Lecture 7: P2P Interest ManagementWei Tsang Ooi
 
CS4344 09/10 Lecture 6: P2P Synchronization
CS4344 09/10 Lecture 6: P2P SynchronizationCS4344 09/10 Lecture 6: P2P Synchronization
CS4344 09/10 Lecture 6: P2P SynchronizationWei Tsang Ooi
 
Cs4344 09/10 Lecture 5: Interest Management
Cs4344 09/10 Lecture 5: Interest ManagementCs4344 09/10 Lecture 5: Interest Management
Cs4344 09/10 Lecture 5: Interest ManagementWei Tsang Ooi
 
CS4344 09/10 Lecture 3: Dead Reckoning and Local Perception Filter
CS4344 09/10 Lecture 3: Dead Reckoning and Local Perception FilterCS4344 09/10 Lecture 3: Dead Reckoning and Local Perception Filter
CS4344 09/10 Lecture 3: Dead Reckoning and Local Perception FilterWei Tsang Ooi
 
CS4344 09/10 Lecture 2: Consistency
CS4344 09/10 Lecture 2: ConsistencyCS4344 09/10 Lecture 2: Consistency
CS4344 09/10 Lecture 2: ConsistencyWei Tsang Ooi
 
CS4344 09/10 Lecture 1: Introduction
CS4344 09/10 Lecture 1: IntroductionCS4344 09/10 Lecture 1: Introduction
CS4344 09/10 Lecture 1: IntroductionWei Tsang Ooi
 
CS5229 09/10 Lecture 11: DNS
CS5229 09/10 Lecture 11: DNSCS5229 09/10 Lecture 11: DNS
CS5229 09/10 Lecture 11: DNSWei Tsang Ooi
 
CS5229 09/10 Lecture 10: Internet Routing
CS5229 09/10 Lecture 10: Internet RoutingCS5229 09/10 Lecture 10: Internet Routing
CS5229 09/10 Lecture 10: Internet RoutingWei Tsang Ooi
 
CS5229 09/10 Lecture 9: Internet Packet Dynamics
CS5229 09/10 Lecture 9: Internet Packet DynamicsCS5229 09/10 Lecture 9: Internet Packet Dynamics
CS5229 09/10 Lecture 9: Internet Packet DynamicsWei Tsang Ooi
 
CS5229 09/10 Lecture 6: Simulation
CS5229 09/10 Lecture 6: SimulationCS5229 09/10 Lecture 6: Simulation
CS5229 09/10 Lecture 6: SimulationWei Tsang Ooi
 
Lecture 0: Introduction to CS5229
Lecture 0: Introduction to CS5229Lecture 0: Introduction to CS5229
Lecture 0: Introduction to CS5229Wei Tsang Ooi
 
Lecture 1: Design Principles of the Internet
Lecture 1: Design Principles of the InternetLecture 1: Design Principles of the Internet
Lecture 1: Design Principles of the InternetWei Tsang Ooi
 
CS4344 Lecture 8: Hybrid Architecture
CS4344 Lecture 8: Hybrid ArchitectureCS4344 Lecture 8: Hybrid Architecture
CS4344 Lecture 8: Hybrid ArchitectureWei Tsang Ooi
 
CS4344 Lecture 10: Player Dynamics
CS4344 Lecture 10: Player DynamicsCS4344 Lecture 10: Player Dynamics
CS4344 Lecture 10: Player DynamicsWei Tsang Ooi
 

Más de Wei Tsang Ooi (20)

SIGMM Education Effort Presentation at Business Meeting
SIGMM Education Effort Presentation at Business MeetingSIGMM Education Effort Presentation at Business Meeting
SIGMM Education Effort Presentation at Business Meeting
 
CS2106 Tutorial 2
CS2106 Tutorial 2CS2106 Tutorial 2
CS2106 Tutorial 2
 
The Computer Science behind YouTube
The Computer Science behind YouTubeThe Computer Science behind YouTube
The Computer Science behind YouTube
 
CS4344 09/10 Lecture 10: Transport Protocol for Networked Games
CS4344 09/10 Lecture 10: Transport Protocol for Networked GamesCS4344 09/10 Lecture 10: Transport Protocol for Networked Games
CS4344 09/10 Lecture 10: Transport Protocol for Networked Games
 
CS4344 09/10 Lecture 9: Characteristics of Networked Game Traffic
CS4344 09/10 Lecture 9: Characteristics of Networked Game TrafficCS4344 09/10 Lecture 9: Characteristics of Networked Game Traffic
CS4344 09/10 Lecture 9: Characteristics of Networked Game Traffic
 
CS4344 09/10 Lecture 8: Hybrid Architecture
CS4344 09/10 Lecture 8: Hybrid ArchitectureCS4344 09/10 Lecture 8: Hybrid Architecture
CS4344 09/10 Lecture 8: Hybrid Architecture
 
CS4344 09/10 Lecture 7: P2P Interest Management
CS4344 09/10 Lecture 7: P2P Interest ManagementCS4344 09/10 Lecture 7: P2P Interest Management
CS4344 09/10 Lecture 7: P2P Interest Management
 
CS4344 09/10 Lecture 6: P2P Synchronization
CS4344 09/10 Lecture 6: P2P SynchronizationCS4344 09/10 Lecture 6: P2P Synchronization
CS4344 09/10 Lecture 6: P2P Synchronization
 
Cs4344 09/10 Lecture 5: Interest Management
Cs4344 09/10 Lecture 5: Interest ManagementCs4344 09/10 Lecture 5: Interest Management
Cs4344 09/10 Lecture 5: Interest Management
 
CS4344 09/10 Lecture 3: Dead Reckoning and Local Perception Filter
CS4344 09/10 Lecture 3: Dead Reckoning and Local Perception FilterCS4344 09/10 Lecture 3: Dead Reckoning and Local Perception Filter
CS4344 09/10 Lecture 3: Dead Reckoning and Local Perception Filter
 
CS4344 09/10 Lecture 2: Consistency
CS4344 09/10 Lecture 2: ConsistencyCS4344 09/10 Lecture 2: Consistency
CS4344 09/10 Lecture 2: Consistency
 
CS4344 09/10 Lecture 1: Introduction
CS4344 09/10 Lecture 1: IntroductionCS4344 09/10 Lecture 1: Introduction
CS4344 09/10 Lecture 1: Introduction
 
CS5229 09/10 Lecture 11: DNS
CS5229 09/10 Lecture 11: DNSCS5229 09/10 Lecture 11: DNS
CS5229 09/10 Lecture 11: DNS
 
CS5229 09/10 Lecture 10: Internet Routing
CS5229 09/10 Lecture 10: Internet RoutingCS5229 09/10 Lecture 10: Internet Routing
CS5229 09/10 Lecture 10: Internet Routing
 
CS5229 09/10 Lecture 9: Internet Packet Dynamics
CS5229 09/10 Lecture 9: Internet Packet DynamicsCS5229 09/10 Lecture 9: Internet Packet Dynamics
CS5229 09/10 Lecture 9: Internet Packet Dynamics
 
CS5229 09/10 Lecture 6: Simulation
CS5229 09/10 Lecture 6: SimulationCS5229 09/10 Lecture 6: Simulation
CS5229 09/10 Lecture 6: Simulation
 
Lecture 0: Introduction to CS5229
Lecture 0: Introduction to CS5229Lecture 0: Introduction to CS5229
Lecture 0: Introduction to CS5229
 
Lecture 1: Design Principles of the Internet
Lecture 1: Design Principles of the InternetLecture 1: Design Principles of the Internet
Lecture 1: Design Principles of the Internet
 
CS4344 Lecture 8: Hybrid Architecture
CS4344 Lecture 8: Hybrid ArchitectureCS4344 Lecture 8: Hybrid Architecture
CS4344 Lecture 8: Hybrid Architecture
 
CS4344 Lecture 10: Player Dynamics
CS4344 Lecture 10: Player DynamicsCS4344 Lecture 10: Player Dynamics
CS4344 Lecture 10: Player Dynamics
 

Último

Judging the Relevance and worth of ideas part 2.pptx
Judging the Relevance and worth of ideas part 2.pptxJudging the Relevance and worth of ideas part 2.pptx
Judging the Relevance and worth of ideas part 2.pptxSherlyMaeNeri
 
Culture Uniformity or Diversity IN SOCIOLOGY.pptx
Culture Uniformity or Diversity IN SOCIOLOGY.pptxCulture Uniformity or Diversity IN SOCIOLOGY.pptx
Culture Uniformity or Diversity IN SOCIOLOGY.pptxPoojaSen20
 
GRADE 4 - SUMMATIVE TEST QUARTER 4 ALL SUBJECTS
GRADE 4 - SUMMATIVE TEST QUARTER 4 ALL SUBJECTSGRADE 4 - SUMMATIVE TEST QUARTER 4 ALL SUBJECTS
GRADE 4 - SUMMATIVE TEST QUARTER 4 ALL SUBJECTSJoshuaGantuangco2
 
ACC 2024 Chronicles. Cardiology. Exam.pdf
ACC 2024 Chronicles. Cardiology. Exam.pdfACC 2024 Chronicles. Cardiology. Exam.pdf
ACC 2024 Chronicles. Cardiology. Exam.pdfSpandanaRallapalli
 
Procuring digital preservation CAN be quick and painless with our new dynamic...
Procuring digital preservation CAN be quick and painless with our new dynamic...Procuring digital preservation CAN be quick and painless with our new dynamic...
Procuring digital preservation CAN be quick and painless with our new dynamic...Jisc
 
Transaction Management in Database Management System
Transaction Management in Database Management SystemTransaction Management in Database Management System
Transaction Management in Database Management SystemChristalin Nelson
 
Influencing policy (training slides from Fast Track Impact)
Influencing policy (training slides from Fast Track Impact)Influencing policy (training slides from Fast Track Impact)
Influencing policy (training slides from Fast Track Impact)Mark Reed
 
Like-prefer-love -hate+verb+ing & silent letters & citizenship text.pdf
Like-prefer-love -hate+verb+ing & silent letters & citizenship text.pdfLike-prefer-love -hate+verb+ing & silent letters & citizenship text.pdf
Like-prefer-love -hate+verb+ing & silent letters & citizenship text.pdfMr Bounab Samir
 
Earth Day Presentation wow hello nice great
Earth Day Presentation wow hello nice greatEarth Day Presentation wow hello nice great
Earth Day Presentation wow hello nice greatYousafMalik24
 
Proudly South Africa powerpoint Thorisha.pptx
Proudly South Africa powerpoint Thorisha.pptxProudly South Africa powerpoint Thorisha.pptx
Proudly South Africa powerpoint Thorisha.pptxthorishapillay1
 
AMERICAN LANGUAGE HUB_Level2_Student'sBook_Answerkey.pdf
AMERICAN LANGUAGE HUB_Level2_Student'sBook_Answerkey.pdfAMERICAN LANGUAGE HUB_Level2_Student'sBook_Answerkey.pdf
AMERICAN LANGUAGE HUB_Level2_Student'sBook_Answerkey.pdfphamnguyenenglishnb
 
ECONOMIC CONTEXT - PAPER 1 Q3: NEWSPAPERS.pptx
ECONOMIC CONTEXT - PAPER 1 Q3: NEWSPAPERS.pptxECONOMIC CONTEXT - PAPER 1 Q3: NEWSPAPERS.pptx
ECONOMIC CONTEXT - PAPER 1 Q3: NEWSPAPERS.pptxiammrhaywood
 
Keynote by Prof. Wurzer at Nordex about IP-design
Keynote by Prof. Wurzer at Nordex about IP-designKeynote by Prof. Wurzer at Nordex about IP-design
Keynote by Prof. Wurzer at Nordex about IP-designMIPLM
 
Difference Between Search & Browse Methods in Odoo 17
Difference Between Search & Browse Methods in Odoo 17Difference Between Search & Browse Methods in Odoo 17
Difference Between Search & Browse Methods in Odoo 17Celine George
 
Concurrency Control in Database Management system
Concurrency Control in Database Management systemConcurrency Control in Database Management system
Concurrency Control in Database Management systemChristalin Nelson
 
Field Attribute Index Feature in Odoo 17
Field Attribute Index Feature in Odoo 17Field Attribute Index Feature in Odoo 17
Field Attribute Index Feature in Odoo 17Celine George
 

Último (20)

Judging the Relevance and worth of ideas part 2.pptx
Judging the Relevance and worth of ideas part 2.pptxJudging the Relevance and worth of ideas part 2.pptx
Judging the Relevance and worth of ideas part 2.pptx
 
Culture Uniformity or Diversity IN SOCIOLOGY.pptx
Culture Uniformity or Diversity IN SOCIOLOGY.pptxCulture Uniformity or Diversity IN SOCIOLOGY.pptx
Culture Uniformity or Diversity IN SOCIOLOGY.pptx
 
GRADE 4 - SUMMATIVE TEST QUARTER 4 ALL SUBJECTS
GRADE 4 - SUMMATIVE TEST QUARTER 4 ALL SUBJECTSGRADE 4 - SUMMATIVE TEST QUARTER 4 ALL SUBJECTS
GRADE 4 - SUMMATIVE TEST QUARTER 4 ALL SUBJECTS
 
ACC 2024 Chronicles. Cardiology. Exam.pdf
ACC 2024 Chronicles. Cardiology. Exam.pdfACC 2024 Chronicles. Cardiology. Exam.pdf
ACC 2024 Chronicles. Cardiology. Exam.pdf
 
Procuring digital preservation CAN be quick and painless with our new dynamic...
Procuring digital preservation CAN be quick and painless with our new dynamic...Procuring digital preservation CAN be quick and painless with our new dynamic...
Procuring digital preservation CAN be quick and painless with our new dynamic...
 
Raw materials used in Herbal Cosmetics.pptx
Raw materials used in Herbal Cosmetics.pptxRaw materials used in Herbal Cosmetics.pptx
Raw materials used in Herbal Cosmetics.pptx
 
FINALS_OF_LEFT_ON_C'N_EL_DORADO_2024.pptx
FINALS_OF_LEFT_ON_C'N_EL_DORADO_2024.pptxFINALS_OF_LEFT_ON_C'N_EL_DORADO_2024.pptx
FINALS_OF_LEFT_ON_C'N_EL_DORADO_2024.pptx
 
Transaction Management in Database Management System
Transaction Management in Database Management SystemTransaction Management in Database Management System
Transaction Management in Database Management System
 
YOUVE_GOT_EMAIL_PRELIMS_EL_DORADO_2024.pptx
YOUVE_GOT_EMAIL_PRELIMS_EL_DORADO_2024.pptxYOUVE_GOT_EMAIL_PRELIMS_EL_DORADO_2024.pptx
YOUVE_GOT_EMAIL_PRELIMS_EL_DORADO_2024.pptx
 
Influencing policy (training slides from Fast Track Impact)
Influencing policy (training slides from Fast Track Impact)Influencing policy (training slides from Fast Track Impact)
Influencing policy (training slides from Fast Track Impact)
 
Like-prefer-love -hate+verb+ing & silent letters & citizenship text.pdf
Like-prefer-love -hate+verb+ing & silent letters & citizenship text.pdfLike-prefer-love -hate+verb+ing & silent letters & citizenship text.pdf
Like-prefer-love -hate+verb+ing & silent letters & citizenship text.pdf
 
Earth Day Presentation wow hello nice great
Earth Day Presentation wow hello nice greatEarth Day Presentation wow hello nice great
Earth Day Presentation wow hello nice great
 
Proudly South Africa powerpoint Thorisha.pptx
Proudly South Africa powerpoint Thorisha.pptxProudly South Africa powerpoint Thorisha.pptx
Proudly South Africa powerpoint Thorisha.pptx
 
AMERICAN LANGUAGE HUB_Level2_Student'sBook_Answerkey.pdf
AMERICAN LANGUAGE HUB_Level2_Student'sBook_Answerkey.pdfAMERICAN LANGUAGE HUB_Level2_Student'sBook_Answerkey.pdf
AMERICAN LANGUAGE HUB_Level2_Student'sBook_Answerkey.pdf
 
ECONOMIC CONTEXT - PAPER 1 Q3: NEWSPAPERS.pptx
ECONOMIC CONTEXT - PAPER 1 Q3: NEWSPAPERS.pptxECONOMIC CONTEXT - PAPER 1 Q3: NEWSPAPERS.pptx
ECONOMIC CONTEXT - PAPER 1 Q3: NEWSPAPERS.pptx
 
Keynote by Prof. Wurzer at Nordex about IP-design
Keynote by Prof. Wurzer at Nordex about IP-designKeynote by Prof. Wurzer at Nordex about IP-design
Keynote by Prof. Wurzer at Nordex about IP-design
 
Difference Between Search & Browse Methods in Odoo 17
Difference Between Search & Browse Methods in Odoo 17Difference Between Search & Browse Methods in Odoo 17
Difference Between Search & Browse Methods in Odoo 17
 
Concurrency Control in Database Management system
Concurrency Control in Database Management systemConcurrency Control in Database Management system
Concurrency Control in Database Management system
 
Model Call Girl in Tilak Nagar Delhi reach out to us at 🔝9953056974🔝
Model Call Girl in Tilak Nagar Delhi reach out to us at 🔝9953056974🔝Model Call Girl in Tilak Nagar Delhi reach out to us at 🔝9953056974🔝
Model Call Girl in Tilak Nagar Delhi reach out to us at 🔝9953056974🔝
 
Field Attribute Index Feature in Odoo 17
Field Attribute Index Feature in Odoo 17Field Attribute Index Feature in Odoo 17
Field Attribute Index Feature in Odoo 17
 

Lecture 4: TCP and TFRC

  • 1. TCP" Reno, NewReno, SACK 4 September 2009 CS5229, Semester 1, 2009/10 1
  • 2. TCP Reno 4 September 2009 CS5229, Semester 1, 2009/10 2
  • 3. 14 cwnd ssthresh 12 10 8 6 4 2 0 4 September 2009 CS5229, Semester 1, 2009/10 3
  • 4. new ack:" if (cwnd < sstresh)" cwnd += 1" else" cwnd += 1/cwnd 4 September 2009 CS5229, Semester 1, 2009/10 5
  • 5. timeout:" retransmit 1st unacked" ssthresh = cwnd/2" cwnd = 1" 4 September 2009 CS5229, Semester 1, 2009/10 6
  • 6. 3rd duplicate ACK:" fast retransmission" (ie, retransmit 1st unack) " fast recovery" (details today)" ssthresh = cwnd = cwnd/2 4 September 2009 CS5229, Semester 1, 2009/10 7
  • 7. TCP’s rule" send more packets if " L + cwnd > H" [ L .. H-1 ] are outstanding packets 4 September 2009 CS5229, Semester 1, 2009/10 10
  • 8. 4 September 2009 CS5229, Semester 1, 2009/10 11
  • 9. Data Packets ACK Packets (received up to this seq number) Congestion Window Sequence Number Time 4 September 2009 CS5229, Semester 1, 2009/10 12
  • 10. 3rd dup ack:" retransmit 1st unacked" ssthresh = cwnd/2" cwnd = cwnd/2 4 September 2009 CS5229, Semester 1, 2009/10 13
  • 11. Incorrectly clamping the congestion window too soon (without fast recovery) X 4 September 2009 CS5229, Semester 1, 2009/10 14
  • 12. fast recovery:" keep the pipe occupied" 4 September 2009 CS5229, Semester 1, 2009/10 15
  • 13. X 4 September 2009 CS5229, Semester 1, 2009/10 16
  • 14. 4 September 2009 CS5229, Semester 1, 2009/10 17
  • 15. X X 4 September 2009 CS5229, Semester 1, 2009/10 18
  • 16. TCP Reno timeout with multiple losses in a window 4 September 2009 CS5229, Semester 1, 2009/10 19
  • 17. TCP NewReno 4 September 2009 CS5229, Semester 1, 2009/10 20
  • 18. X X 4 September 2009 CS5229, Semester 1, 2009/10 21
  • 19. 4 September 2009 CS5229, Semester 1, 2009/10 22
  • 20. 3rd dup ack:" retransmit 1st unacked" ssthresh = cwnd/2" cwnd = cwnd/2 + 3" remember highest 4 September 2009 CS5229, Semester 1, 2009/10 25
  • 21. “complete” ack:" (all are acked) " cwnd = ssthresh 4 September 2009 CS5229, Semester 1, 2009/10 26
  • 22. “partial” ack:" (acknowledge n packets)" retransmit" cwnd = cwnd - n + 1 4 September 2009 CS5229, Semester 1, 2009/10 27
  • 23. Note: RFC2581/RFC2582 give the accurate/gory details. Simplified version is presented here (eg. cwnd vs FlightSize, update of cwnd upon partial ACK). 4 September 2009 CS5229, Semester 1, 2009/10 29
  • 24. What does a dup ACK tell us? 4 September 2009 CS5229, Semester 1, 2009/10 30
  • 25. “Coarse Feedback” 4 September 2009 CS5229, Semester 1, 2009/10 31
  • 26. TCP SACK 4 September 2009 CS5229, Semester 1, 2009/10 32
  • 27. Use TCP header options to report received segments. 4 September 2009 CS5229, Semester 1, 2009/10 33
  • 28. SACK Blocks:" 1st block - report most recently received segments" subsequent blocks - repeat most recent previous blocks 4 September 2009 CS5229, Semester 1, 2009/10 34
  • 29. pipe: num of outstanding packets in the pipe." send only if pipe < cwnd 4 September 2009 CS5229, Semester 1, 2009/10 35
  • 30. scoreboard: which packets have been received? 4 September 2009 CS5229, Semester 1, 2009/10 36
  • 31. X X 4 September 2009 CS5229, Semester 1, 2009/10 37
  • 32. 3rd dup ack:" pipe = cwnd - 3" retransmit 1st unacked" ssthresh = cwnd/2" cwnd = cwnd/2 + 3 4 September 2009 CS5229, Semester 1, 2009/10 38
  • 33. subsequent dup ack:" cwnd++" pipe--" if pipe < cwnd" send packet, pipe++ 4 September 2009 CS5229, Semester 1, 2009/10 39
  • 34. “partial” ack:" retransmit" cwnd = cwnd - n + 1" pipe -= 2" if pipe < cwnd" send packet, pipe++ 4 September 2009 CS5229, Semester 1, 2009/10 40
  • 35. Idea of SACK:" Which packet has left the network?" Where is the gap?" Decouple when to send and what to send. 4 September 2009 CS5229, Semester 1, 2009/10 43
  • 36. TCP SACK recovers faster than NewReno with multiple losses in a window. 4 September 2009 CS5229, Semester 1, 2009/10 44
  • 37. Deployment 4 September 2009 CS5229, Semester 1, 2009/10 57
  • 38. Feb 2004 NewReno Reno 8% Tahoe 15% 77% 4 September 2009 CS5229, Semester 1, 2009/10 58
  • 39. 70% " SACK capable 4 September 2009 CS5229, Semester 1, 2009/10 59
  • 40. TCP BIC/CUBIC" Linux 2.6.x 4 September 2009 CS5229, Semester 1, 2009/10 63
  • 41. Compound TCP " MS Windows Vista 4 September 2009 CS5229, Semester 1, 2009/10 64
  • 42. TFRC" equation-based" congestion control 4 September 2009 CS5229, Semester 1, 2009/10 65
  • 43. Not everyone uses TCP 4 September 2009 CS5229, Semester 1, 2009/10 66
  • 44. UDP:" Media streaming" Gaming" VoIP 4 September 2009 CS5229, Semester 1, 2009/10 67
  • 45. Why not congestion controlled?" 1. UDP has low delay, no need full reliability. UDP " is not congestion controlled. 4 September 2009 CS5229, Semester 1, 2009/10 68
  • 46. Why not congestion controlled?" 2. No incentive. OTOH, there are incentives NOT to use congestion control. 4 September 2009 CS5229, Semester 1, 2009/10 69
  • 48. “Unresponsive Flows” 4 September 2009 CS5229, Semester 1, 2009/10 71
  • 49. Bad: lead to unfairness and congestion collapse. 4 September 2009 CS5229, Semester 1, 2009/10 72
  • 50. Unfairness: unresponsive flows consume more bandwidth than congestion controlled flows. 4 September 2009 CS5229, Semester 1, 2009/10 73
  • 51. Congestion Collapse: wasting bandwidth by sending packets that will be dropped 4 September 2009 CS5229, Semester 1, 2009/10 77
  • 52. Today: " a TCP-friendly" unreliable protocol 4 September 2009 CS5229, Semester 1, 2009/10 78
  • 53. Idea: " send at a rate that a TCP flow would send 4 September 2009 CS5229, Semester 1, 2009/10 79
  • 54. we can do the AIMD-thing" at the source, or 4 September 2009 CS5229, Semester 1, 2009/10 80
  • 55. 4 September 2009 CS5229, Semester 1, 2009/10 81
  • 56. equation-based " congestion control 4 September 2009 CS5229, Semester 1, 2009/10 82
  • 57. steady" fair" responsive 4 September 2009 CS5229, Semester 1, 2009/10 83
  • 58. how to determine" RTT" tRTO" p 4 September 2009 CS5229, Semester 1, 2009/10 84
  • 59. p is not packet loss rate" but " loss event rate 4 September 2009 CS5229, Semester 1, 2009/10 85
  • 60. 4 September 2009 CS5229, Semester 1, 2009/10 86
  • 61. 4 September 2009 CS5229, Semester 1, 2009/10 87
  • 62. 4 September 2009 CS5229, Semester 1, 2009/10 88
  • 63. RTT can fluctuates 4 September 2009 CS5229, Semester 1, 2009/10 89
  • 64. 4 September 2009 CS5229, Semester 1, 2009/10 90
  • 65. 4 September 2009 CS5229, Semester 1, 2009/10 91
  • 66. 4 September 2009 CS5229, Semester 1, 2009/10 92
  • 67. 4 September 2009 CS5229, Semester 1, 2009/10 93
  • 68. how to initialize? 4 September 2009 CS5229, Semester 1, 2009/10 94
  • 69. slow start" (until loss occur)" Tnow = min(2Tprev, 2Trecv) 4 September 2009 CS5229, Semester 1, 2009/10 95
  • 70. no loss history, how?" solve p given T, RTT 4 September 2009 CS5229, Semester 1, 2009/10 96
  • 71. 4 September 2009 CS5229, Semester 1, 2009/10 97
  • 72. TFRC is now part of DCCP 4 September 2009 CS5229, Semester 1, 2009/10 98