ATM switching node design based on a versatile traffic descriptor

Abstract

Because of the high speed, the provision of unrestricted bandwidth on demand by ATM-based B-ISDN can only be satisfied by sacrificing network resource utilization. In ATM networks, the network resources are link bandwidth and node buffer space. A new traffic descriptor which directly specifies the resource requirements of ATM traffic streams in terms of bandwidth, buffer space and a set of parameter adjustment rules is proposed. We call this a versatile traffic descriptor (VTD) because it can describe relevant characteristics of all ATM traffic streams including nonstationary traffic streams. Also, the VTD incorporates both the traffic description and the user's QoS specifications. Therefore, there is no need to specify the QoS requirements separately. A radically new, VTD-based switching node design, which uses novel per-connection buffering scheme and service scheduling scheme is also proposed. It is conjectured that the proposed earliest due date (EDD) service scheduling scheme is optimal in per-connection burstiness reduction.