Abstract: An asynchronous transfer mode inverse multiplexed communication system is disclosed wherein a series of communication cells are multiplexed over a set of communication links. Each communication cell includes a framing bit of a predetermined framing bit stream for each communication link and a control channel bit of a control message for each communication link. Inbound communication cells from each communication link are aligned according to the corresponding framing bit stream. The control message specifies an ordered list of logical identifiers to indicate a multiplexed sequence of transfer of the communication cells over the communication links.

Abstract: A frame based traffic policing system that determines if incoming data cells are conforming or non-conforming according to the a traffic contract. The frame based traffic policing system first detects a cell at the beginning or end of a frame and determines if the frame conforms with a traffic contract. If the cell does not exceed the parameters of the traffic contract, then the frame based traffic policing system deems the cell as conforming. If the cell was the first cell of a frame, then frame based traffic policing system treats all the remaining cells in the frame as conforming or non-conforming depending upon if the first data cell was conforming or non-conforming. If the cell was the last cell of a frame, then frame based traffic policing system treats all the cells of the following frame as conforming or non-conforming depending upon if the last cell of a previous frame was conforming or non-conforming.

Abstract: An asynchronous transfer mode inverse multiplexed communication system is disclosed wherein a series of communication cells are multiplexed over a set of communication links. Each communication cell includes a framing bit of a predetermined framing bit stream for each communication link and a control channel bit of a control message for each communication link. Inbound communication cells from each communication link are aligned according to the corresponding framing bit stream. The control message specifies an ordered list of logical identifiers to indicate a multiplexed sequence of transfer of the communication cells over the communication links.

Abstract: To simplify the service decision made in a queue based digital switch, a method and apparatus is introduced that makes service decisions based upon the history of incoming cells. The apparatus includes a minimum service rate circuit that monitors the rate of arriving cells. The minimum service rate circuit tests the arriving cells to determine if they are in conformance with the minimum service rate of a service contract. The minimum service rate circuit may use a continuous state leaky bucket algorithm as specified in the CCITT Recommendation I.371 document, dated 1992, to determine if a cell is in conformance with the minimum service rate of the service contract. When a cell arrives that conforms to the minimum service rate, the minimum service rate circuit notifies the server and the server serves the queue associated with the connection.

Abstract: A mechanism for routing a communication cell in a cell switching communication controller that employs multiple path identifier masking functions selected by a header control field in the communication cell and that employs a content addressable memory comprising a plurality of entries, wherein each entry stores a pre configured local termination identifier and a pre configured pass through identifier.

Abstract: A method and apparatus for exchanging communication cells in a communication controller, wherein an arbiter determines transmission requests for each of a plurality of communication modules in the communication controller. Each communication module has a transmit signal line and a receive signal line coupled to a switching circuit in the communication controller. The arbiter selectively couples the transmit signal lines to the receive signal lines according to the transmission requests. The communication modules transmit communication cells through the switching circuit, while the arbiter determines new transmission requests from each communication module.

Abstract: A mechanism for buffering communication cells in a communication controller, wherein a cell queuing circuit provides a cell loss priority mechanism, and wherein the cell queuing circuit determines service states for queue channels according to bandwidth allocation parameters. The service states includes a serve.sub.-- now state, a serve.sub.-- ok state, and a no.sub.-- serve state, such that a queue channel is in the serve.sub.-- now state if the queue channel must be serviced to maintain a minimum information rate parameter for the queue channel, the serve.sub.-- ok state if the queue channel can be serviced and not exceed a peak information rate parameter for the queue channel.

Abstract: A method and apparatus for use in a cell network node for initial routing and rerouting of connections to a slave node based on ordering candidate slave connections, searching existing connections for candidate best routes and validating the selected best route comparing actual route delays and available bandwidth with maximum allowable delays and loading of the candidate slave connection. The invention also provides for programmable queuing delays by controlling queue lengths and for improved justification of reassembled information using actual maximum node delays.

Abstract: A feedback control system for congestion prevention in a cell (packet) switching communication network is described. Congestion control is accomplished by controlling the transmission rate of bursty traffic in the presence of high priority, voice, low speed statistical, high speed deterministic and multicast data. Because bursty traffic is relatively insensitive to delay, adequate buffer capacity can be provided at the network nodes in order to minimize bursty data cell loss. By monitoring the buffer queue lengths at the nodes, a control signal can be generated at each intermediate node indicating the state of congestion. Excess queue length indicates incipient congestion while short queue lengths indicate excess capacity. Queue status is forwarded to the destination node where it is interpreted and sent back to the source node as a feedback rate control signal using a 2-bit code.

Abstract: A method of fair queuing and servicing cell traffic in a telecommunication node which interfaces with a telecommunication system including a multiplicity of nodes is described. The steps include placing cells of traffic are placed in a queue according to a hopcount associated with each cell of bursty traffic, the hopcount being representative of the number of nodes traversed by the associated cell. Cells of traffic within the queue are serviced according to their associated hopcount. The hopcount associated with each cell of traffic is incremented as each cell of traffic is serviced. Circuitry providing fair queuing and servicing of cell traffic in a telecommunication node which interfaces with a telecommunication system including a multiplicity of nodes is also described.

Abstract: A packet communications network and apparatus for communicating information in voice and data packets transmits and receives voice and data in accordance with standardized frames of a standardized communications format such as a standard DS-1 type trunk. An apparatus is coupled to multiplex standardized channels into a single channel wherein voice or data signals are packetized into independently addressable packets synchronized on, for example, the DS-1 frame. The network includes voice and packet data concentration apparatus operable in a multiple node trunk environment to concentrate signals into independently addressable synchronously switchable packets, thereby to provide an efficient (high density capacity) interface between trunk terminations. Up to four times as much information can be transferred between nodes with the ability to switch between nodes as compared to conventional TDM and PCM communication without compression without the ability to switch between nodes.

Abstract: A packet communications network and apparatus for communicating information in voice and data packets transmits and receives voice and data in accordance with standardized frames of a standardized communications format such as a standard DS-1 type trunk. An apparatus is coupled to multiplex standardized channels into a single channel wherein voice or data signals are packetized into independently addressable packets synchronized on, for example, the DS-1 frame. The network includes voice and packet data concentration apparatus operable in a multiple node trunk environment to concentrate signals into independently addressable synchronously switchable packets, thereby to provide an efficient (high data capacity) interface between trunk terminations. Up to four times as much information can be transferred between nodes with the ability to switch between nodes as compared to conventional TDM and PCM communication without compression without the ability to switch between nodes.

Abstract: A packet communications network and apparatus for communicating information in voice and data packets transmits and receives voice and data in accordance with standardized frames of a standardized communications format such as a standard DS-1 type trunk. An apparatus is coupled to multiplex standardized channels into a single channel wherein voice or data signals are packetized into independently addressable packets synchronized on, for example, the DS-1 frame. The network includes voice and packet data concentration apparatus operable in a multiple node trunk environment to concentrate signals into independently addressable synchronously switchable packets, thereby to provide an efficient (high data capacity) interface between trunk terminations. Up to four times as much information can be transferred between nodes with the ability to switch between nodes as compared to conventional TDM and PCM communication without compression without the ability to switch between nodes.

Abstract: An improved architecture for a computerized branch exchange particularly for a time division multiplexed bus used in the exchange. An intershelf bus includes a unidirectional source bus which receives signals from expanders and a unidirectional destination bus which transmits signals to the expanders. The expanders, through another bus, communicate with line cards which interface with telephone station sets, commercial lines, etc. A time division multiplexed controller updates distributed connection tables contained in each of the expanders and controls the flow of data onto and from the unidirectional buses. The distributed connection tables eliminate the need to broadcast addresses during each time slot. The arrangement is particularly useful in reducing blocking associated with prior art bidirectional buses.