AT&T Labs Research — Leading Invention, Driving Innovation

The present invention provides a method, computer-readable medium and device for dynamically managing allocation of bandwidth in a packet network using a Dynamic Setting Scheme (DSS) for Class Based Queuing (CBQ). The method includes the steps of maintaining a minimized reserved portion of bandwidth to minimize delay jitter and maximizing a shared portion of bandwidth to maximize overall bandwidth utilization. Allocation of bandwidth may be based on a sharing tree hierarchical scheme that provides for temporary borrowing of bandwidth by real-time applications from bandwidth of non-real-time applications and blocks borrowing of bandwidth by non-real-time applications from bandwidth of real-time applications. DSS typically provides for using measurable parameters, such as queue length and number of borrowing attempts per a predetermined length of time/observation window, as control triggers for implementing adjustment of bandwidth allocation. In one embodiment, the steps include measuring a predetermined parameter at predetermined observation window times and dynamically adjusting allocated bandwidth for parent classes of real-time traffic by adjusting an average of the predetermined parameter to have a value within a predetermined stable region.

The present invention provides a method, computer-readable medium and device for dynamically managing allocation of bandwidth in a packet network using a Dynamic Setting Scheme (DSS) for Class Based Queuing (CBQ). The method includes the steps of maintaining a minimized reserved portion of bandwidth to minimize delay jitter and maximizing a shared portion of bandwidth to maximize overall bandwidth utilization. Allocation of bandwidth may be based on a sharing tree hierarchical scheme that provides for temporary borrowing of bandwidth by real-time applications from bandwidth of non-real-time applications and blocks borrowing of bandwidth by non-real-time applications from bandwidth of real-time applications. DSS typically provides for using measurable parameters, such as queue length and number of borrowing attempts per a predetermined length of time/observation window, as control triggers for implementing adjustment of bandwidth allocation. In one embodiment, the steps include measuring a predetermined parameter at predetermined observation window times and dynamically adjusting allocated bandwidth for parent classes of real-time traffic by adjusting an average of the predetermined parameter to have a value within a predetermined stable region.

A method and system for dynamically triggering flow-based quality of service shortcuts through a router is disclosed. The method further includes the steps of receiving a data packet at a router, determining whether a shortcut has been set up for a data flow to which said packet belongs, checking the status of an onset trigger counter when no shortcut exists, and when a current value of said onset trigger exceeds an onset trigger value, setting up a new shortcut for said data packet belonging to said data flow. The method of the present invention includes a dynamic system for adjusting state variable to control the number of shortcuts in existence and the adjusting the shortcut set up rate for optimal router switching efficiency.

In a node that receives cells for many connections, a method discards entire packets when the node's buffer is full. The selected connection is one that includes at least one cell that corresponds to the beginning of a packet. In another embodiment, the connection is chosen by first making an initial selection, determining whether that selection can stand, and if not, by making an alternate selection. When an alternate selection is made, a credit factor associated with the initial selection is decremented, while the credit factor of the alternate selection is incremented. The initial selection can be carried out by considering the overall traffic load at the node, the individual traffic loads that comprise the overall traffic load of the node, and the QoS that is desired for the various connections that are active in the node.

Methods, systems and computer program products are provided for evaluating requests for a network connection combining the requested network connection with existing connections so as to provide a representation of the total network connections and accepting the request for a network connection if sufficient resources are available to accept the request for a network connection based upon the representation of the total network connections. Particular embodiments of the present invention determine if sufficient resources are available to accept the request for a network connection based upon diffusion based representations of the existing network connections and the requested network connection and accepting the request for a network connection if sufficient resources are available to accept the request for a network connection. The diffusion based representation may be used to determine the capacity required for existing connections and the requested connection based upon a predefined maximum loss ratio (L).