Abstract: In packet communication, a method for automatically classifying packet flows for use in allocating bandwidth resources and the like by a rule of assignment of a service level. By rendering discoverable the attributes of a flow specification for packet flows, a finer grained hierarchy of classification is provided automatically that is based on information which is specific to the type of program or application supported by the flow and thus allowing greater flexibility in control over different flows within the same application. The method comprises applying individual instances of traffic classification paradigms to packet network flows based on selectable information obtained from a plurality of layers to define a characteristic class, then mapping the flow to the defined traffic class. The flow specification is provided with some application-specific attributes, some of which are discoverable.

Abstract: In a packet communication environment, a method is provided for automatically classifying packet flows for use in allocating bandwidth resources by a rule of assignment of a service level. The method comprises applying individual instances of traffic classification paradigms to packet network flows based on selectable information obtained from a plurality of layers of a multi-layered communication protocol in order to define a characteristic class, then mapping the flow to the defined traffic class. It is useful to note that the automatic classification is sufficiently robust to classify a complete enumeration of the possible traffic.

Abstract: In a packet telecommunications environment, a method is provided for end to end explicit rate control through a plurality of heterogeneous internetworked networking topologies comprising networks without explicit rate signaling, such as TCP/IP based LAN subnets, and networks with explicit network layer rate signaling, such as Frame Relay permanent or switched virtual circuits (PVC/SVC) or ATM available bit rate (ABR) services by reallocating bandwidth in a partition using a Committed Information Rate of the portion comprising the virtual circuits for a partition size. In specific embodiments, the invention may exist as an integrated device, such as an enhanced FRAD, or a bandwidth management device, which detects congested network conditions from information obtained indirectly from a FRAD or network edge device using techniques such as reading the network edge device's MIB.

Abstract: A method of JPEG compression of an image frame divided up into a plurality of non-overlapping, tiled 8×8 pixel blocks Bij where i, j are integers covering all of the blocks in the image frame. A global quantization matrix Q is determined by either selecting a standard JPEG quantization table or selecting a quantization table such that the magnitude of each quantization matrix coefficient, Qij is inversely proportional to a visual importance, Iij, to the image of a corresponding DCT basis vector. Next a linear scaling factor Sij is selected which defines bounds over which the image is to be variably quantized. Transform coefficients, Dijmn, obtained from a digital cosine transform of Bij, are quantized and the quantized coefficients Tijmn and Q*Smin are entropy encoded, where Smin is a user selected minimum scaling factor, to create a JPEG image file. The algorithm is unique in that it allows for the effect of variable-quantization to be achieved while still producing a fully compliant JPEG file.

Abstract: In a packet communication environment, a method is provided for automatically classifying packet flows for use in allocating bandwidth resources by a rule of assignment of a service level. The method comprises applying individual instances of traffic classification paradigms to packet network flows based on selectable information obtained from a plurality of layers of a multi-layered communication protocol in order to define a characteristic class, then mapping the flow to the defined traffic class. It is useful to note that the automatic classification is sufficiently robust to classify a complete enumeration of the possible traffic.

Abstract: In a packet communication environment, a method is provided for automatically classifying packet flows for use in allocating bandwidth resources by a rule of assignment of a service level. The method comprises applying individual instances of traffic classification paradigms to packet network flows based on selectable information obtained from a plurality of layers of a multi-layered communication protocol in order to define a characteristic class, then mapping the flow to the defined traffic class. It is useful to note that the automatic classification is sufficiently robust to classify a complete enumeration of the possible traffic.

Abstract: A switching device for forwarding network traffic to a desired destination on a network, such as a telephone or computer network. The switching device includes multiple ports and uses a lookup table containing lookup keys to determine which port to forward network traffic over. The lookup tables are populated based on use. Consequently, the lookup tables on different ports contain different addresses. By storing only addresses that a port uses, each port's lookup table is unique to that port's characteristics. Additionally, aging techniques are used on both source and destination addresses in the lookup table so that stale entries are removed and memory is conserved.

Abstract: A method for explicit data rate control is introduced into a packet communication environment (10) which does not have data rate supervision by adding latency to the acknowledgment (ACK) packet and by adjusting the size of the flow control window associated with the packet in order to directly control the data rate of the source data at the station (12 or 14) originating the packet.

Abstract: A method of processing frames received at a sending port of a switching device for communication to a destination port includes storing in the switching device an offset value, a comparator value, and an expectant value; comparing information located at a position in a frame determined by the offset value with the comparator value to obtain an outcome; and processing the frame with the outcome. Processing the frame may include communicating the frame to a destination port or setting the priority of the frame. The offset and comparator values may be part of a filter that also includes an anchor value from which the offset value is measured and a mask value that masks the frame information before comparison with the comparator value. Where there are a multiple of filters in the switching device, the method may include combining the filter outcomes to obtain a filter group outcome; and processing the frame with the group outcome. Combining the filter outcomes may include logically combining their outcomes.

Abstract: A method for explicit data rate control is introduced into a packet communication environment (10) which does not have data rate supervision by adding latency to the acknowledgment (ACK) packet and by adjusting the size of the flow control window associated with the packet in order to directly control the data rate of the source data at the station (12 or 14) originating the packet.

Abstract: In a packet communication environment, a method is provided for classifying packet network flows for use in determining a policy, or rule of assignment of a service level, and enforcing that policy by direct rate control. The method comprises applying individual instances of traffic objects, i.e., packet network flows to a classification model based on selectable information obtained from a plurality of layers of a multi-layered communication protocol, then mapping the flow to the defined traffic classes, which are arbitrarily assignable by an offline manager which creates the classification. It is useful to note that the classification need not be a complete enumeration of the possible traffic.

Abstract: A method is provided for optimally setting the receiver window size in a flow controlled protocol in order to minimize queuing in a packet telecommunications network. Embodiments according to the present invention are operable at an explicit path to identify per connection information from host address or physical interface, flow direction, or any combination of these elements. The present invention may function in conjunction with a rate detection method that determines both a message serialization delay component and a data size invariant delay component.

Abstract: A method for pacing data flows in packet switched networks by arranging data transmission over a period of time based upon a set of ascertainable factors about the underlying transmission link to derive an intersegment transmission interval. The intersegment transmission interval can be used to pace either data packets or acknowledgment packets. The method is especially useful for pacing the transmission of data in a digital data packet communication environment having a plurality of digital packet transmission stations inter-connectable in a data path and employing the Transmission Control Protocol (TCP) suite.

Abstract: In a packet communication environment, a method is provided for classifying packet network flows for use in determining a policy, or rule of assignment of a service level, and enforcing that policy by direct rate control. The method comprises applying individual instances of traffic objects, i.e., packet network flows to a classification model based on selectable information obtained from a plurality of layers of a multi-layered communication protocol, then mapping the flow to the defined traffic classes, which are arbitrarily assignable by an offline manager which creates the classification. It is useful to note that the classification need not be a complete enumeration of the possible traffic.

Abstract: A method for explicit data rate control is introduced into a packet communication environment (10) which does not have data rate supervision by adding latency to the acknowledgment (ACK) packet and by adjusting the size of the flow control window associated with the packet in order to directly control the data rate of the source data at the station (12 or 14) originating the packet.

Abstract: A method is provided for preventing gratuitous retransmission of data from being propagated through a network which includes holding data to be retransmitted for a minimum time period. If an acknowledgment occurs while the retransmitted data is still being held, then the retransmitted data is discarded rather than propagated through the network. The invention also provides for selectively holding retransmissions based upon ascertainable factors about the underlying connection activity, such as number of successful transmissions.

Abstract: A method for data flow rate detection useful with data flow rate control is introduced into a TCP packet communication environment which does not have data rate supervision by computing presumed speed based on latency between packets during the initial interchange of synchronization (SYN) packet and the acknowledgement (ACK) packet, presuming to know the initial length of each. This information may be utilized to determine potential rate of data flow for further use in making bandwidth allocation and rate enforcement decisions.

Abstract: A two-way (interactive) cable television system is disclosed which has distributed processing and which employs a cable-distribution subsystem that includes corrective regenerators each of which ignores noise (invalid signals) and, when overloaded, ignores (rejects) certain valid signals so as to favor older information (commands).