Patent ID: 6751195
Filing Date: 2004-06-15
Classification: H04L

Abstract:
A communication control device for providing an ABR service function to an ATM-based network, comprising;an RM cell receiving unit receiving an incoming RM cell from a source terminal via a forward transmission line; and a point-to-multipoint backward RM cell transmitting unit overwriting, when a congestion at a downstream portion of the network is detected, a congested-condition ER value and a congestion notification data to the incoming RM cell received by the RM cell receiving unit, and the backward RM cell transmitting unit transmitting a point-to-multipoint backward RM cell containing the congested-condition ER value and the congestion notification data, to an upstream communication control device via a single backward transmission line, so that a state of the congestion is notified to the upstream communication control device; wherein the point-to-multipoint backward RM cell has a routing tag, and the point-to-multipoint backward RM cell transmitting unit overwrites a predetermined value to the routing tag of the point-to-multipoint backward RM cell when the congestion is detected, the predetermined value of the routing tag indicating that the point-to-multipoint backward RM cell should be copied to all backward RM cells directed to all destinations in the network with respect to the communication control device.