Congestion control pdf
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On success for last window, increase window linearly based congestion control misinterprets loss as a signal of congestion, leading to low throughput. routers routers In this article, we examine and compare some of the most prominent recent re on the use of machine learning to redesign congestion control protocols, with an Introduction. (to not overflow receiver) Sources perform Congestion control (to not overload network) Source and destination participate in “Connection” set-up and tear-down Receiver Window vs. Packet forwarding: input port to output port. Congestion Window •Flow control –Keep a fast senderfrom overwhelming a slow receiver •Congestion control –Keep a set of sendersfrom overloading the network •Different concepts, but similar mechanisms –TCP flow control: receiver window –TCP congestion control: congestion window –Sender TCP window = The congestion control protocol is also called “transport protocol”. Transport: end-to-end, reliability, flow control, and congestion control Congestion: informally: “too many sources sending too much data too fast for the network to handle”. results of congestion: long delays (e.g. Only in gateways, at the convergence of flows, is there enough information to control sharing and fair allocation Routing protocols: computing port mappings. Lecture material taken from “Computer Networks A Systems Approach”, Third Ed.,Peterson and Davie, Morgan Kaufmann, TCP Congestion Congestion Control Two conflicting goals-Provider: high utilization-User: fairness among users Want to converge to a state where everyone getsN Avoid congestion TCP (Reliable, In Order Delivery) Source send segments. Narrow waist of IP: unreliable, best-effort datagram delivery. Source retransmits lost and/or corrupted segments. Transmission Control Protocol (TCP) is a popular protocol − provides reliable transmission − when all users exhibit “good-citizen” behavior − but has higher delay (cost of reliability) User Data-gram Protocol (UDP) is another protocol − unreliable and user rease sending rate by a linear factor (e.g. Additive increase, multiplicative rease. Fixing these problems requires an alternative to loss-based congestion Figureillustrates the end-to-end hostCC architecture. buffer overflow at routers) limited link capacity limited link buffers 4 Future work: the gateway side of congestion control. Let Li be queue length at time i In steady state: Li = N, where N is a constant During congestion, Li = N + yLi-1, where y >Consequence: queue size increases multiplicatively.» Must reduce sending rate multiplicatively as well This distributed coordination is the key to both fairness and stability. BBR synchronizes flows around the desirable event of an empty bottleneck queue. Internet is a network of networks. Computer networks have experienced an explosive growth over the past few years and with that growth have come severe congestion problems. For example, it is The links are later unpaused when the buffer becomes uncongested. On packet loss, divide congestion window in half. divide by 2) Rough intuition for why this works. In this sec-tion, we provide details on the three key technical ideas embodied within the architecture—host congestion Two broad approaches towards congestion control: Network-assisted congestion End-end congestion control: control: routers participate in congestion control. queueing in router buffers) lost packets (e.g. Sources perform Flow control. Destinations send ACKs. While algorithms at the transport endpoints can insure the network capacity isn’t exceeded, they cannot insure fair sharing of that capacity. By contrast, loss-based congestion control synchronizes around the undesirable events of periodic queue growth and overflow, amplifying delay and packet loss LectureCongestion ControlLecture. This paper is a theoretical study of the stability and fairness properties of network level congestion The Many Failings of TCP Congestion ControlFills up queues (large queueing delays)Every segment not ACKed is a loss (non-congestion related losses)Produces TCP Congestion Control. TCP Congestion Control.
Rating: 4.3 / 5 (3677 votes)
Downloads: 45759
CLICK HERE TO DOWNLOAD
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.
.
.
.
.
.
.
.
.
On success for last window, increase window linearly based congestion control misinterprets loss as a signal of congestion, leading to low throughput. routers routers In this article, we examine and compare some of the most prominent recent re on the use of machine learning to redesign congestion control protocols, with an Introduction. (to not overflow receiver) Sources perform Congestion control (to not overload network) Source and destination participate in “Connection” set-up and tear-down Receiver Window vs. Packet forwarding: input port to output port. Congestion Window •Flow control –Keep a fast senderfrom overwhelming a slow receiver •Congestion control –Keep a set of sendersfrom overloading the network •Different concepts, but similar mechanisms –TCP flow control: receiver window –TCP congestion control: congestion window –Sender TCP window = The congestion control protocol is also called “transport protocol”. Transport: end-to-end, reliability, flow control, and congestion control Congestion: informally: “too many sources sending too much data too fast for the network to handle”. results of congestion: long delays (e.g. Only in gateways, at the convergence of flows, is there enough information to control sharing and fair allocation Routing protocols: computing port mappings. Lecture material taken from “Computer Networks A Systems Approach”, Third Ed.,Peterson and Davie, Morgan Kaufmann, TCP Congestion Congestion Control Two conflicting goals-Provider: high utilization-User: fairness among users Want to converge to a state where everyone getsN Avoid congestion TCP (Reliable, In Order Delivery) Source send segments. Narrow waist of IP: unreliable, best-effort datagram delivery. Source retransmits lost and/or corrupted segments. Transmission Control Protocol (TCP) is a popular protocol − provides reliable transmission − when all users exhibit “good-citizen” behavior − but has higher delay (cost of reliability) User Data-gram Protocol (UDP) is another protocol − unreliable and user rease sending rate by a linear factor (e.g. Additive increase, multiplicative rease. Fixing these problems requires an alternative to loss-based congestion Figureillustrates the end-to-end hostCC architecture. buffer overflow at routers) limited link capacity limited link buffers 4 Future work: the gateway side of congestion control. Let Li be queue length at time i In steady state: Li = N, where N is a constant During congestion, Li = N + yLi-1, where y >Consequence: queue size increases multiplicatively.» Must reduce sending rate multiplicatively as well This distributed coordination is the key to both fairness and stability. BBR synchronizes flows around the desirable event of an empty bottleneck queue. Internet is a network of networks. Computer networks have experienced an explosive growth over the past few years and with that growth have come severe congestion problems. For example, it is The links are later unpaused when the buffer becomes uncongested. On packet loss, divide congestion window in half. divide by 2) Rough intuition for why this works. In this sec-tion, we provide details on the three key technical ideas embodied within the architecture—host congestion Two broad approaches towards congestion control: Network-assisted congestion End-end congestion control: control: routers participate in congestion control. queueing in router buffers) lost packets (e.g. Sources perform Flow control. Destinations send ACKs. While algorithms at the transport endpoints can insure the network capacity isn’t exceeded, they cannot insure fair sharing of that capacity. By contrast, loss-based congestion control synchronizes around the undesirable events of periodic queue growth and overflow, amplifying delay and packet loss LectureCongestion ControlLecture. This paper is a theoretical study of the stability and fairness properties of network level congestion The Many Failings of TCP Congestion ControlFills up queues (large queueing delays)Every segment not ACKed is a loss (non-congestion related losses)Produces TCP Congestion Control. TCP Congestion Control.
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