Abstract: This system is made to perform congestion detection and flow control in high speed digital packet switching network (22) carrying discardable and non-discardable traffic. Forward traffic received at a destination system over a first connection from a source system is monitored. If a congestion-indicating bit is detected in a received packet, a backward congestion indicator is set in packets flowing from the destination system to the source system over a second connection. The source system integrates the number of backward congestion indicators received over successive periods of time using a count-up, count-down counter. Specific congestion control actions are taken at the source system as a function of the counter state at the end of each of the successive periods of time. The congestion control actions may include increasing or decreasing the bandwidth allocated to discardable traffic intended to be delivered over the first connection.

Abstract: A packet scheduling system for use in a switching node of a high speed packet switching network. Incoming packets are enqueued in connection queues. Each connection is classified as red (exceeding traffic profile) or green (within traffic profile). QOS priority is also identified for each connection. Packets are dequeued for transmission as a function of priority class and connection class. Higher priority class connections have priority over lower priority class connections. Within a given priority class of connections, green connections have priority over red connections. Round robin scheduling is used for packets from connections in the same priority and connection class. In addition, a dynamic priority coupling mechanism is provided to prevent red higher priority traffic from blocking green lower priority traffic.