An approach to controlling congestion in ATM networks

1995

ABSTRACT: An end-to-end adaptive rate-based control scheme is currently being considered by the ATM Forum for supporting Available Bit Rate (ABR) services. The scheme is a reactive control where the source adapts its transmission rate based on feedback from the network. The adaptation can be linear or exponential, while the information received from the network can be based on a forward or backward explicit congestion indication.

Teletraffic Science and Engineering, 1994

Cet article présente un nouveau mécanisme de gestion de congestions destiné aux commutateurs ATM. En effet, la plupart des propositions actuelles prennent en compte uniquement les contraintes de la couche ATM. Le push-out proposé dans cet article intègre à la fois les contraintes de la couche ATM et de la couche AAL en utilisant une définition particulière du bit CLP. Dès qu'une cellule d'un message est rejetée, notre algorithme rejette les autres cellules du même message (ainsi que les cellules non arrivées dans le tampon). Ces rejets groupés permettent de libérer plus d'espace pour les autres messages et augmentent ainsi la probabilité qu'ils arrivent intacts à destination. Notre objectif est de montrer qu'en cas de congestion, les commutateurs rejettent les cellules sans aucune information au niveau de la structure des messages. Ainsi à destination, tous les messages incomplets sont rejetés car la couche ATM est incapable de détecter les pertes de cellules et ne fournit aucun mécanisme de reprise sélective des erreurs. Enfin, nous présentons les taux de rejets de cellules et de messages obtenus par simulation de plusieurs mécanismes de rejets sélectifs.

Proceedings of IEEE INFOCOM '96. Conference on Computer Communications

We consider the combined control problem of connection admission, flow rate, and bandwidth allocation (capacity, service-rate) under nonstationary conditions. A fluid flow model in state variable form describes the time varying mean behaviour of Available Bit Rate (ABR) traffic, which competes with Guaranteed Traffic for network resources. Using nonlinear control we derive an integrated control strategy, for the finite buffer and finite server case, that is insensitive to any propagation delay. We also derive bounds on mix between ABR and Guaranteed traffic to ensure that control strategy is effective, and select control design variables which can be used to influence the delivered QoS. The performance of proposed scheme is evaluated using analysis and simulation. Simulation results show that it achieves effective server and buffer utilisation (as predicted by analysis) and by appropriate choice of control design variables achieves prescribed bounded delays (for Guaranteed traffic only) and zero cell loss (even for ABR traffic demands exceeding server capacity, which if not controlled would cause losses). Hence proposed scheme delivers guaranteed QoS to user and avoids retransmissions, thus increasing network utilisation.

Computers & Industrial Engineering, 1993

In order to guarantee a committed Quality of Service (QoS) to the users of a Broadband Integrated Services Digital Network (B-ISDN), preventive congestion control becomes critical, and is implemented through Call Acceptance Control (CAC), Usage Parameter Control (UPC), and Space Priority functions. Currently, Asynchronous Transfer Mode (ATM) cells are equipped with a 1-bit Cell Loss Priority (CLP) field, which can be used for serviceoriented and/or UPC marking. This creates a conflict, since these two marking approaches may have contradicting objectives, and are designed to operate independently. Moreover, by admitting excessive cells as marked traffic, this group is allowed to grow uncontrollably, thereby jeopardizing the QoS committed to other (low priority) marked cells.

To meet the demands of multiservice networking, in which traffic of varying bandwidth and delay requirements must be simultaneously serviced, sophisticated traffic and resource management mechanisms are needed. To serve these needs, your ATM switch router uses a shared-memory architecture that offers advanced traffic management and congestion control capabilities. The traffic management features of the ATM switch router provide the following capabilities: • Integrated support for different types of ATM services • Flexible policies for bandwidth allocation through controlled link-sharing services. • Effective use of network resources • The congestion control capabilities of the ATM switch router support the following goals: Avoid conditions where congestion can occur. • Minimize the effects of congestion when it does occur. • Prevent spreading the congestion state to other parts of the network. The specific resource management capabilities of your ATM switch router are platform dependent.

1996

Congestion control mechanisms for ATM networks as selected by the ATM Forum traffic management group are described. Reasons behind these selections are explained. In particular, selection criterion for selection between rate-based and credit-based approach and the key points of the debate between these two approaches are presented. The approach that was finally selected and several other schemes that were considered are described.

The paper proposes a generic traffic control specification at the UNI unifying the characteristics of credit-based and rate-based schemes, and allowing implementation of both, along with other traffic control schemes, simultaneously, in an ATM network.

IFIP advances in information and communication technology, 2000

This paper exploits classical control theory to design congestion control algorithms for "best effort" traffic in ATM networks. The control goal is the full utilisation of network links without incurring cell losses. A fluid model approximation of cell flows is assumed and linear differential equations are used to model the dynamics of network queues in response to ABR traffic and quality constrained (CBR+ VBR) traffic. The available ABR bandwidth is modelled by means of an unknown and bounded disturbance function. A general end to end control algorithm that feeds back to the source the space that is free in the network buffers is included in the model and a particular one is proposed which is based on Smith's principle. The linearity and the simplicity of the proposed control law allow us to prove, via mathematical analysis, that the algorithm always guarantees no cell losses whereas full utilisation of network links is ensured if the capacity of per-VC buffers is at least equal to the VC bandwidth-delay product. Moreover, per-VC queuing easily allows switches to enforce fairness. Finally, it is shown how performance evaluation can be easily carried out using SIMULINK for MATLAB, which is a software tool widely used by control engineers to simulate dynamic systems. In this way, the effort to develop discrete event simulations is saved.

American Journal of Networks and Communications, 2015

In this Paper, Computer-based Simulation models for effective Congestion control and Traffic management in Asynchronous Transfer Mode (ATM) network have been developed providing a basis for monitoring ATM networks performance for traffic and congestion control purposes ,providing a system with a reduce short-term congestion in ATM networks, and enhancing a fair operation of networks in spite of the challenges in designing ATM traffic management system to make maximal use of network resources. An IDCC scheme was implemented, applying IDCC methodology to the ATM Network. Using analysis performance, limits were created for robust controlled network behaviour, as dictated by reference values of the desired queue length. By tightly controlling output of the controller, the overall network performance was adjusted and also controlled. A simulation tool, MATLAB/SIMULINK, was used for this purpose. An improvement was observed in the delay performance of ATM networks. The results were obtained by running several simulations and populating a table with the outcome over a number of simulation runs. The effectiveness of the congestion control techniques was tested by analysing the dynamic performance of the model through variation of some parameters. The performance of this model proved to be efficient if applied in the ATM network of today.

Proceedings of the 4th WSEAS …, 2005

Abstract. Proportional control methods of controlling congestion in high speed ATM networks fail to achieve the desired performance due to the action delays, nonlinearities, and uncertainties in control loop. In this paper an adaptive minimum variance controller is proposed to ...