Abstract: A method and system is provided to enable quality of service across a backplane switch for multicast packets. For multicast traffic, an egress queue manager manages congestion control in accordance with multicast scheduling flags. A multicast scheduling flag is associated with each egress queue capable of receiving a packet from a multicast ingress queue. When the multicast scheduling flag is set and the congested egress queue is an outer queue, the egress queue manager refrains from dequeueing any marked multicast packets to the destination ports associated with the congested outer queue until the congestion subsides. When the congested egress queue is a backplane queue, the egress queue manager refrains from dequeuing any marked multicast packets to the destination ports on the destination blade associated with the congested backplane queue until the congestion subsides.

Abstract: Methods, systems, and computer program products for allocating excess bandwidth of an output among network users are disclosed. According to one method, packets associated with a plurality of network users for forwarding to an output are received. The packets can include a first non-committed information rate (CIR) packet associated with a first network user. The method can include a step for maintaining a count of non-CIR packets sent for the first network user. Further, the method can include preventing the first non-CIR packet from being forwarded to the output in response to the count having a predetermined relationship with respect to a threshold level.

Abstract: Methods and systems for fine grain bandwidth allocation are disclosed. According to one method, input is received from a user in a standard bandwidth denomination indicating bandwidth to be provided by a switched network element. The bandwidth is automatically converted into a base bandwidth value and a residual bandwidth value. The base bandwidth value is converted to a number of tokens to be placed in a token bucket every predetermined token bucket refresh interval. The residual bandwidth value is converted into a second number of tokens and a number of predetermined token bucket refresh intervals over which the second number of tokens is to be placed in the token buckets. The token buckets are then refreshed in accordance with the base and residual bandwidth values and the token bucket refresh intervals. The queue is serviced in accordance with available tokens in the token buckets.

Abstract: A method and system is provided to enable quality of service across a backplane switch. An egress queue manager on one blade communicates with an ingress queue manager on the same or on another blade where each blade is connected via a backplane switch. The egress queue managers communicate the congestion to ingress queue managers using a messaging scheme. The ingress queue managers determine when to reduce or resume the packet sending rates of ingress queues mapped to congested egress queues or to destinations on congested blades. Each ingress queue manager maintains information about the status of egress queue congestion on its own blades. Normal rates of dequeuing packets from ingress queues are resumed only when the related congestion on all of the egress queues or related destinations has subsided.

Abstract: A method and system is provided to enable quality of service across a backplane switch. An egress queue manager on one blade communicates with an egress queue manager on another blade where each blade is connected via a backplane switch. When a blade becomes congested, egress queues mapped to a destination on the congested blade also become congested. The egress queue managers determine when to reduce or resume the packet sending rates of egress queues mapped to destinations on congested blades using a messaging scheme. Each egress queue manager maintains notifications of the status of egress queue congestion on its own and other blades. Normal rates of dequeuing packets are resumed only when the related congestion on all of the blades has subsided.

Abstract: A method and system is provided to enable quality of service across a backplane switch for multicast packets. For multicast traffic, an egress queue manager manages congestion control in accordance with multicast scheduling flags. A multicast scheduling flag is associated with each egress queue capable of receiving a packet from a multicast ingress queue. When the multicast scheduling flag is set and the congested egress queue is an outer queue, the egress queue manager refrains from dequeueing any marked multicast packets to the destination ports associated with the congested outer queue until the congestion subsides. When the congested egress queue is a backplane queue, the egress queue manager refrains from dequeuing any marked multicast packets to the destination ports on the destination blade associated with the congested backplane queue until the congestion subsides.