Abstract: A method, system, and computer-readable medium for integrating multiple techniques for processing data communications is described in which the processing steps shared by multiple of the techniques do not have to be duplicated by each of the techniques. In some situations, some or all of the multiple processing techniques are performed in parallel, such as on different processors. In some situations, a Multi-Protocol Edge Switch (“MPEX”) is used to integrate multiple processing techniques for received data communications that are to be forwarded to a destination, such as by performing protocol translation, performing load balancing between multiple alternative destinations on one or more of the networks to which the MPEX belongs, performing firewall and other content-based analysis for any or all of the nodes on one or more of the networks to which the MPEX belongs, and/or providing content-based routing of data communications in order to identify appropriate destinations.

Abstract: An end to end forwarding architecture includes a memory hub having a first ingress interface for receiving packets from a source port. The packets have associated ingress flow identifiers. A second ingress interface outputs the packets to a switch fabric. An ingress controller manages how the packets are queued and output to the switch fabric. The same memory hub can be used for both per flow queuing and per Class of Service (CoS) queuing. A similar structure is used on the egress side of the switch fabric. The end to end forwarding architecture separates per flow traffic scheduling operations performed in a traffic manager from the per flow packet storage operations performed by the memory hub.

Abstract: A virtual reality system initiates desired real world actions in response to defined events occurring within a virtual environment. A variety of systems, such as communications devices, computer networks, and software applications, may be interfaced with the virtual reality system and made responsive to virtual events. For example, the virtual reality system may trigger a communications system to establish a communications link between people in response to a virtual event. Users, represented as avatars within the virtual environment, generate events by interacting with virtual entities, such as other avatars, virtual objects, and virtual locations. Virtual entities can be associated with specific users, and users can define desired behaviors for associated entities. Behaviors control the real world actions triggered by virtual events. Users can modify these behaviors, and the virtual reality system may change behaviors based on changing conditions, such as time of day or the whereabouts of a particular user.

Abstract: A system and method for a packet VRU which directly utilize packet network protocols, such as those of the H.323 standard, to provide enhanced services via a packet network, such as whisper mode communications, call recording, call broadcasting, advertisement broadcasting during calls, one-number service, and operator services. In a preferred embodiment of the present invention, the packet VRU establishes control of media streams, such as through the use of separate signaling channels associated with various communication devices, in order to provide desired enhanced call services.

Abstract: The present invention provides a method and apparatus to determine the state of a communications link between two nodes in a network. Typically, each node will have an RTT-based value to use, a packets sent counter, and a threshold number to use against the packet sent counter to determine if there is a problem with their communications link. Using the RTT value makes the failure detection sensitive to the actual state of the communications link at any particular time; it also allows the failure detection algorithm to take into account the bursty nature of nodes in a packetized network connection. For each packet received from a non-local node, the local node sets the counter to 0 and starts a new RTT-based time interval. The local node then increments the counter only once, regardless of how many packets it sends to the non-local node, during the RTT-based time interval. Once the time interval is up, the counter is incremented for each packet sent.

Abstract: A method for synchronizing a timing device of a client station via a communications network is disclosed. A plurality of packets is sent from a time server to the client station via the communications network. Upon receipt of the plurality of packets at the client station a time indicative of a local time of receipt of the plurality of packets is determined and the plurality of packets are returned to the time server via the communications network. Upon receipt of the plurality of packets at the time server data in dependence upon round trip delay of the packets and variance in packet spacing are determined and compared to threshold values. If the determined data are within the threshold values data indicative of a time correction are determined and sent from the time server to the client station.

Abstract: A method of handling data packets in a network switch is disclosed. The method includes placing incoming packets into an input queue and applying the input data packets to an address resolution logic engine. A lookup is performed to determine whether certain packet fields are stored in a lookup table; and the result of the lookup is also examined to determine if it provides a trunk group ID for a particular data packet of the input data packets. When the lookup provides a trunk group ID, the trunk group ID is used to determine an egress port and the particular data packet is forwarded to the egress port. Alternatively, the packet is discarded, forwarded, or modified based upon the result of the lookup, where the lookup does not provide a trunk group ID. A network switch using the method is also disclosed and methods directed to mirroring of data packets are also disclosed.

Abstract: Techniques to determine the rate for a data transmission in an OFDM system. The maximum data rate that may be reliably transmitted over a given multipath (non-flat) channel by the OFDM system is determined based on a metric for an equivalent (flat) channel. For the given multipath channel and a particular rate (which may be indicative of a particular data rate, modulation scheme, and coding rate), the metric is initially derived from an equivalent data rate and the particular modulation scheme. A threshold SNR needed to reliably transmit the particular data rate using the particular modulation scheme and coding rate is then determined. The particular rate is deemed as being supported by the multipath channel if the metric is greater than or equal to the threshold SNR. Incremental transmission is used to account for errors in the determined data rate.

Abstract: Techniques to determine the rate for a data transmission in an OFDM system. The maximum data rate that may be reliably transmitted over a given multipath (non-flat) channel by the OFDM system is determined based on a metric for an equivalent (flat) channel. For the given multipath channel and a particular rate (which may be indicative of a particular data rate, modulation scheme, and coding rate), the metric is initially derived from an equivalent data rate and the particular modulation scheme. A threshold SNR needed to reliably transmit the particular data rate using the particular modulation scheme and coding rate is then determined. The particular rate is deemed as being supported by the multipath channel if the metric is greater than or equal to the threshold SNR. Incremental transmission is used to account for errors in the determined data rate.

Abstract: A mechanism is provided for supporting differentiated services (quality of service) in a radio network. A radio access system is provided which supports the quality of service in data packet transmission over its air interface. The system comprises a selection of predefined default radio flows having different quality of service characteristics and means (4, 52) for selecting a radio flow having appropriate quality of service characteristics for the packet to be transmitted over the air interface from the selection.

Abstract: A method of operating a data transmission network (10) is described comprising at least two outer rings (11, 13) and a middle ring (12) which are coupled to one another via nodes (14, 15, 16). One of the nodes (14) represents a central node for all three rings (11, 12, 13). Switching devices (23, 24, 25, 26) for the establishment of connections are contained in each of the nodes (14, 15, 16). It is recognized that a connection is to be established from the one outer ring (11, 13) to the other outer ring (13, 11) via the middle ring (12). Then the connection is established taking into account all three rings (11, 12, 13).

Abstract: A method of carrying out arbitration in a packet exchanger including an input buffer temporarily storing a packet having arrived at an input port, and a packet switch which switches a packet between a specific input port and a specific output port, includes the steps of (a) concurrently carrying out a first plurality of sequences in each of the sequences basic processes for at least one of the input buffer and the output port are carried out in a predetermined order, and (b) making an allowance in each of the sequences for packets to be output through output ports at different times from one another.

Abstract: A telephony network for enabling the origination and termination of telephone calls between one or more subscriber terminals connected to a public packet network with an open addressing protocol and one or more non-subscriber terminals connected to a PSTN network. Subscribers to the telephony network have E.164 numbers mapped to their current IP address and published by a mapping server so other subscribers and non-subscribers can call the subscriber. The mapped information is published on either a HTML or XML page for direct use over the Internet by other subscribers or for use by a gateway device. The gateway device enables non-subscribers on the PSTN to directly call subscribers. Calls between subscribers completely by-pass the PSTN. Subscribers can also call anyone with a phone number whether they are a subscriber or not.

Abstract: A communications network includes a communications medium with a synchronous communications transport signal including time-division-multiplexed (TDM) channels, bridges having respective interfaces to different local area network (LAN) segments, and add-drop circuits coupling associated ones of the bridges to the communications medium. Each add-drop circuit groups TDM channels of the communications transport signal into a bundle, and schedules the use of the bundle to carry data traffic originated by the associated bridge and to carry data traffic originated by the other bridges. Data traffic originated by the associated bridge and destined for the other bridges is transmitted on the bundle in accordance with the scheduling. For data traffic received from the other bridges via the bundle, it is determined whether the received data traffic is destined for the associated bridge, and if so then it is forwarded to the associated bridge.

Abstract: A system and method for a packet VRU which directly utilize packet network protocols, such as those of the H.323 standard, to provide enhanced services via a packet network. The packet VRU generally operates within the packet network and is not required to provide data format translation or multiple device-type access. In a preferred embodiment of the present invention, the packet VRU redirects the media stream from a source so that it is sent directly to a destination, instead of passing through the packet VRU. Alternatively, if the packet VRU must perform processing on the message contents, the packets may be sent to both the destination and to the packet VRU. The packet VRU may still retain call control over the media streams by maintaining the signaling and user input components of the call.

Abstract: The invention relates to a packet transmission network operating according to a packet switching method, comprising a plurality of network nodes coupled via at least two rings working in opposite directions which each have in status tables entries about the location of a defect and switched loops from one ring to another ring in a network node. After detecting a repaired defect, a network node changes an entry in its status table and transmits a repair message of this type about the location of the repaired defect to all the network nodes that can be reached.

Abstract: Layered multicast provides a method of optimizing the reception data rate for a plurality of networked push media receivers having heterogeneous reception bandwidth. To reduce the latency of a pull medium element during multimedia event, the data rates for push media layers are reduced during transmission of the pull medium. Further, a recently added layer of the push medium is dropped when the transmission of the push medium is initiated and attempts of the receiver to subscribe to a higher push medium layer are suppressed during pull medium reception.

Abstract: During G3FAX communication with an IP network 30, a FAX adapter 10 controls a packet size data storage 100d with the use of a control signal 14, generated by a packet size controller 10e, to adjust the packet size of FAX data sent from a G3FAX 20 according to delay information 12f from the IP network 30. When sending data to the IP network 30, the adapter 10 allows the size of a packet to be adjusted in response to the delay information 12f sent from the IP network 30, thus resolving a discrepancy in transfer speed.

Abstract: A system and method have been provided for programming synchronization features of a multidimensional digital frame structure. Such a frame structure acts as a digital wrapper, and includes overhead, payload, and forward error correction (FEC) sections. Words in the overhead section are used to synchronize the frame structure. The described invention permits the location of the frame synchronization bytes (FSBs) to be made programmable, so that the system and method are flexible for changes in communication protocols. This flexibility also impacts the number, the value, bandwidth, and the allowable bit error rate (BER) of the located FSBs.

Abstract: A communications system includes a data network that is coupled to an access system, which enables access to the data network by a client system. The client system issues requests through a router and the access system, with the requests specifying a server system as the destination. The server system sends response messages back to the client system through the data network and the router. The router is capable of modifying an indication of the maximum size of at least a portion of a message. This ensures that response messages communicated by the server system are not too large that the access system is unable to handle the response messages.