Recently, there has been much interest in admission control schemes that place the burden of admission control decisions on the end users. In these schemes, referred to as Endpoint Admission Control. the decision to join the network is taken by the user, based on the probing of the network using probe packets. Depending on the level of congestion, routers mark the probe packets and thus inform ...

We study the effect of Explicit Congestion Notification on TCP performance for two simultaneous large file transfers. We compare this performance with that achieved using other congestion avoidance mechanisms, namely Drop Tail and RED. Our results show that TCP performance improves, in certain cases significantly, with ECN both for individual flows and the network as a whole.

Delivering congestion signals is essential to the performance of networks. Current TCP/IP networks use packet losses to signal congestion. Packet losses not only reduces TCP performance, but also adds large delay. Explicit Congestion Notification (ECN) delivers a faster indication of congestion and has better performance. However, current ECN implementations mark the packet from the tail of the...

Current TCP flow control depends on packet losses to find the workload that a network can support. Packet drops not only reduce TCP performance, but also add large transfer delay to the packets. Instead of dropping the overflowed packets, Explicit Congestion Notification (ECN) detects incipient congestion and notifies the sources to reduce their windows when the queue length exceeds a threshold...

̋ We overview in this paper the enhancement of TCP’s congestion control mechanisms using Explicit Congestion Notification (ECN) over ATM networks. Congestion is indicated by not only packet losses as is currently the case but an agent implemented at the network’s edge as well. The agent bridges the gap between the ATM layer and the TCP layer in the protocol stack at the receiver end and coordina...

This note describes a proposed addition of ECN (Explicit Congestion Notification) to IP. TCP is currently the dominant transport protocol used in the Internet. We begin by describing TCP’s use of packet drops as an indication of congestion. Next we argue that with the addition of active queue management (e.g., RED) to the Internet infrastructure, where routers detect congestion before the queue...

This paper proposes to modify the TCP congestion control mechanism by allowing network routers to supply Explicit Buffer Notification (EBN) to the TCP data sender. The TCP sender runs an algorithm that uses the EBN feedback to compute the control window. The EBN plays the role of a generalized Advertised Window so that the EBN TCP results to be a natural extension of the current TCP flow contro...

We investigate the behavior of a new response strategy to TCP Explicit Congestion Notification (ECN). The new strategy is more aggressive in the short term, but preserves TCP long term behavior– without modifying the router ECN marking rate. A more aggressive short term behavior gives incentives for hosts to become ECN-compliant. ECN serves as an early warning sign in this case. Our analysis de...

Congestion control with the positive use of explicit notification that indicates internal network conditions is a promising way to address the performance issues of congestion control in high-speed networks. We previously proposed SIRENS, a scalable, robust, and flexible fine-grained explicit notification framework where each router captures a snapshot of the various kinds of downstream link st...