A flexible, policy-based, mechanism for managing, monitoring, and prioritizing traffic within a network and allocating bandwidth to achieve true quality of service (QoS) is provided. According to one aspect of the present invention, a method is provided for managing bandwidth allocation in a network that employs a non-deterministic access protocol, such as an Ethernet network. A packet forwarding device receives information indicative of a set of traffic groups, such as: a MAC address, or IEEE 802.1p priority indicator or 802.1Q frame tag, if the QoS policy is based upon individual station applications; or a physical port if the QoS policy is based purely upon topology. The packet forwarding device additionally receives bandwidth parameters corresponding to the traffic groups. After receiving a packet associated with one of the traffic groups on a first port, the packet forwarding device schedules the packet for transmission from a second port based upon bandwidth parameters corresponding to the traffic group with which the packet is associated. According to another aspect of the present invention, a method is provided for managing bandwidth allocation in a packet forwarding device. The packet forwarding device receives information indicative of a set of traffic groups. The packet forwarding device additionally receives information defining a QoS policy for the traffic groups. After a packet is received by the packet forwarding device, a traffic group with which the packet is associated is identified. Subsequently, rather than relying on an end-to-end signaling protocol for scheduling, the packet is scheduled for transmission based upon the QoS policy for the identified traffic group.
This is a continuation of application Ser. No. 09/597,878, filed on Jun. 20, 2000 now U.S. Pat. No. 6,678,248, which is a continuation of Ser. No. 09/018,103 filed on Feb. 3, 1998 issued U.S. Pat. No. 6,104,700.
Stations of a communication network have internal queues for accumulating and transmitting data messages over a shared communication channel. Each queue within a station accumulates and transmits data messages that have a different level of priority than those accumulated and transmitted by other internal queues of that station. While preferential access to the shared channel is given to data messages having higher levels of priority, data messages having the same priority are transmitted according to a set of rules common to all of the stations. That is, a queue in one of the stations is configured to delay and/or transmit data messages of a given priority level according to a set of rules that applies identically to the queue of any other station that handles data messages of that same priority level. Transmission opportunities are thus fairly allocated between all queues containing data messages of the same priority level.
A method and apparatus for controlling the admission of data packets into a network element is described. In an embodiment, a method for controlling admittance of a data packet into a memory buffer includes performing, prior to queuing the data packet for routing by a processor, the following: (1) receiving a data packet from one of at least two different ports, (2) determining a priority value within the data packet, and (3) determining an admittance group identifier for the data packet based on the priority value and the port the data packet was received. The method also comprises queuing the data packet from the memory buffer to one of a number of queues for routing by the processor upon determining that a number of data packets stored in the memory buffer and having the admittance group identifier is not greater than a threshold value.
A communication device integrates traffic monitoring, policy configuration and enforcement, and proxy services within the device. The policies can affect both prioritization of data as well as allocation of communication bandwidth. Data packets that are accepted at the device are classified according to a set of defined classes and are transmitted through the device according to a policy for prioritization and bandwidth allocation for the classes. Optionally, some of the packets are passed to a proxy application hosted in the communication device. The device functions as a link-layer bridge, thereby allowing the device to be inserted into a data path without reconfiguring network layer software at devices that use that data path. The device includes operating modes in which packets are passed through the device without modification.
