Active Window Management: An Efficient Gateway Mechanism for TCP Traffic Control

Abstract

Many techniques have been proposed in the last few years to address performance degradations in end-to-end congestion control. Although these techniques require parameter tuning to operate in different congestion scenarios, they miss the challenging target of both minimizing network delay and keeping goodput close to the network capacity. In this paper we propose a new mechanism, called Active Window Management (AWM), which addresses these targets by stabilizing the queue length in the network gateways. AWM acts on the Advertised Window parameter in the TCP segment carrying the acknowledge, but it does not affect the TCP protocol. The proposed technique is implemented in the network access gateways, that is, in the gateways through which both the incoming and outgoing packets related to a given TCP connection are forced to go, whatever the routing strategy used in the network. We show that when the access gateways implementing AWM are the bottleneck in the networks, TCP performance is very close to that of a pseudo constant bit rate protocol providing no loss, while network utilization is close to one.

An Energy-aware Routing Mechanism for Latency-sensitive Traffics

“… If the output buffer input rate is less than the service rate, we use AWM [33] to increase the traffic sending rate.…”

Active Window Management: Performance Assessment through an Extensive Comparison with XCP

“…In this paper we extend the work in [7] with an extensive analysis of the AWM performance. Moreover we compare AWM with XCP and demonstrate that, when the access router implementing AWM is the bottleneck in the network, TCP performs very closely to XCP, providing no loss and very high network utilization.…”

“…In [7], we have presented an analytical fluid model of the AWM gateway to be used for the choice of the appropriate values of β in order to obtain the desired performance.…”

“…A previous work of the same authors [7] presents an early proposal of a new mechanism, called Active Window Management (AWM), which is able to maintain the queue length in routers implementing it very close to a given target value, while, at the same time, avoiding packet losses. In this paper we extend the work in [7] with an extensive analysis of the AWM performance.…”

Analysis of ECN/RED and SAP-LAW with simultaneous TCP and UDP traffic

“…is the number of TCP connections at time t. It is noteworthy to point out, that the formula above computes the maximum amount of bandwidth share that can be allocated to a TCP connection while the resulting amount of data is computed by multiplying the computed bandwidth share with the flows current round trip time (RTT) measurement [25,26,27]. Work [25] proposes an extension to SAP-LAW, addressing the RTT fairness problem amongst TCP flows.…”