Abstract: An initial address allocating unit 11 allocates a predetermined address to each of the nodes 21 connected to respective first stage switches 22. A connecting state acquiring unit 12 acquires a connecting state from each of the first stage switches 22, each of second stage switches 23 and each of third stage switches 24. An erroneous connection detecting unit 13 compares the connecting state acquired by the connecting state acquiring unit 12 with a prestored predetermined connecting state, thereby detecting an erroneous connection. An address changing unit 14 changes an address of the node 21 allocated by the initial address allocating unit 11 to satisfy a first predetermined condition based on the connecting state, when the erroneous connection is detected by the erroneous connection detecting unit 13.

Abstract: A diagnostic tool is provided for calculating the availability of multi-segment pseudowires within an internet protocol (IP)-based mobile backhaul network. A control message is transmitted from an originating node towards a destination node within the IP-based mobile backhaul network over a primary multi-segment pseudowire and a secondary multi-segment pseudowire. From the response messages received from intermediate nodes positioned between the network node and the destination node along the primary multi-segment pseudowire and the secondary multi-segment psuedowire, the originating node determines the identities of each of the intermediate nodes, and calculates a respective individual availability of the primary multi-segment pseudowire and the secondary multi-segment pseudowire.

Abstract: A method, system and diagnostic tool for diagnosing a problem in CSPF and non-CSPF MPLS networks, including problems with LDP tunnels. This includes one or more of the following: hopping from network element to network element; determining whether an LSP between elements is operational; determining whether the hop was strict or loose; evaluating whether there is an existing path between the elements; finding and remembering an IGP link between the elements; recognizing whether the LSP is an FRR LSP; diagnosing a cause of the LSP between the elements being down; and altering a display of a topology map of the network to indicate the cause of the problem.

Abstract: Disclosed is an apparatus comprising a first network node configured to transmit a first message to a second network node, wherein the first message comprises data designating the first network node as a member of a first multicast channel, and wherein the first message comprises data indicating a network address a third network node that is designated as a last hop router (LHR) of the first multicast channel. Also disclosed is a method comprising sending, by a first network node, a protocol independent multicast (PIM) join message, wherein the PIM join message comprises the network address of a PIM channel last hop router (LHR).

Abstract: A communication system for propagating time division multiplexing (TDM) fault notifications has a first interworking function (IWF) of a packet network and a second IWF of the packet network. The second IWF detects a TDM fault of a TDM network and transmits continuity check messages (CCMs) to the first IWF. Further, the second IWF controls the CCMs in response to a detection of the TDM fault such that a TDM fault notification is propagated from the second IWF to the first IWF based on the CCMs, and the first IWF propagates the TDM fault notification to a second TDM node via a TDM signal.

Abstract: An outage notification system is provided which includes a first communication network, a second communication network, a plurality of first communication units communicatively coupled to the first communication network and the second communication network, a network monitoring unit communicatively coupled to the first communication network and configured to detect a failure in at least one of the plurality of first communication units or the first communication network, a plurality of second communication units communicatively coupled to the second communication network and associated with corresponding first communication units, and a message alert unit communicatively coupled to the first and second communication networks and configured to receive an alert notification from the network monitoring unit via the first communication network indicating a failure in at least one of the first communication units or the first communication network.

Abstract: A switch fabric for a modular router may be tested without connecting the switch fabric portion of the router to the other modular portions of the router. The switch fabric may generate test data units and insert the test data units into one or more elements of the switch fabric. The switch fabric may operate with the inserted test data units. A control component may receive data units from the switch fabric after operation of the switch fabric and analyze the received data units to determine whether the received data units correspond to the inserted test data units.

Abstract: A voice-over-internet system and method is disclosed which comprises a gateway (40) and a separate remote gateway (50) which can each provide signals between a radio (12) and a user terminal (24) via the internet (22). If one of the gateways fails, the other gateway is able to take over the communication role. Data is synchronised between the gateways and a polling protocol is used to determine whether one of the gateways remains active or whether the other gateway should assume the active role.

Abstract: Aspects of a method and system for determination and exchange of network timing information are provided. In this regard, for each network hop traversed by a packet, a propagation delay of said network hop may be determined. Moreover, the propagation delay, and/or a hop length calculated utilizing the propagation delay, may be appended to the packet. The packet may, for example, be a MMRP registration packet or a SRP reservation packet. The packet may be dropped in instances that the propagation delay and/or length of a one or more traversed network hops is outside a determined range. The hop length may be determined by multiplying the propagation delay by a speed of propagation on the hop. The speed of propagation may be determined based on the physical layer technology associated with the network hop. Digital rights management may be implemented for media communicated on the network hop based at least in part on the hop length or the propagation delay.

Abstract: A method for detecting errors on an audio/video (A/V) data stream in a data service network includes providing multicast components operably coupled to each other via respective links for transmitting the A/V data stream to a user and for defining at least one multicast tree. The method further includes generating a state information signal indicative of a number of errors on the A/V data stream for at least one of the links and at least one of the plurality of multicast components. The method further includes determining the cumulative number of errors on the A/V data stream that are indicative of the number of errors for the at least one of the links and the at least one of the plurality of multicast components in the multicast tree in response to the state information signal.

Abstract: Instead of alternatively utilizing only one fabric or the other fabric of a redundant pair, both fabrics simultaneously transmit duplicate information, such that each packet forwarding module (PFM) receives the output of both fabrics simultaneously. In real time, an internal optics module (IOM) analyzes each information chunk coming out of a working zero switch fabric; simultaneously examines a parallel output of a working one duplicate switch fabric; and compares on a chunk-by-chunk basis the validity of each and every chunk from both switch fabrics. The IOM does this by examining forward error correction (FEC) check symbols encapsulated into each chunk. FEC check symbols allow correcting a predetermined number of bit errors within a chunk. If the chunk cannot be corrected, then the IOM provides indication to all PFMs downstream that the chunk is defective. Under such conditions, the PFMs select a chunk from the non-defective switch fabric.

Abstract: A network information analyzing method is disclosed for determining the status of a network including plural communication apparatuses.

Abstract: A method for identifying disruptions using network and systems data includes receiving resource utilization information for a network component at a first time and receiving resource utilization information for the network component at a second time. The method also includes identifying a resource utilization pattern for the network component, predicting a resource utilization for the network component at a third time based on the resource utilization pattern, and determining whether the predicted resource utilization will breach a utilization threshold for the network component.

Abstract: Methods and systems are described that improve the alarming logic for Border Gateway Protocol (BGP) flapping events. Embodiments provide an alarm threshold on BGP flapping conditions and alert on BGP related events. A reduction in silent failures and network outage minutes is achieved.

Abstract: Disclosed are an expandable network system and a redundant method applied to the system. According to one embodiment, the network system may be a ring-type or linear-type network system. A plurality of network nodes form one or more sub-networks. Many interconnected sub-networks form another network. While the network system is initialized, the method defines the role of each network port of each network node in each sub-network. Concurrently, every network port interconnected between the sub-networks is also defined to be a blocked port or a forward port. This mechanism defining the role of each port not only prevents the possible broadcast storm occurred in the network system, but also modifies the network signaling path by re-defining the roles of the ports while the connection changes. Therefore, the expandable network system and the method achieve a fast-redundant connection scheme, and the more flexible network-expanding function.

Abstract: A method for reporting a channel status in a mobile communication system including a relay station (RS) is provided. When a mobile terminal in the coverage of a base station (BS) receives a service through an RS, the RS reports a channel status between the RS and the terminal to the BS to allow the BS to decide whether or not to communicate with the terminal through the RS. In the method, a first RS in communication with a BS and at least one terminal measures a channel quality with a first terminal and compares the measured channel quality with a threshold and transmits a report message to the BS according to the comparison. The report message is to request the BS to measure a channel quality of at least one of a second RS and the first terminal in communication with the BS.

Abstract: In a computing system environment, an arrangement of computing devices includes multiple layers behind a content flow director, such as an L4 switch in a web service. In a computing device of an outermost layer directly communicating with the content flow director, a communications port is conditionally enabled upon policy being met or exceeded in the computing system environment behind the content flow director. If unmet, the communications port is disabled, if already enabled, or prevented from becoming enabled, if not otherwise already enabled. In this manner, policy establishes port enablement. In certain aspects, policy determinations include determining a time of response, a quality of service check or a pass/fail condition of the one of the computing devices. Policy is also easily implemented as remote or local computer executable instructions on the computing devices. Representative computing devices include switches, such as L4 switches, routers, servers, repeaters, adapters or the like.

Abstract: The embodiment of the present invention relates to a method, device and system for processing service traffic based on pseudo wires, wherein the method includes: receiving service traffic from a customer edge device (101); determining a pseudo wire aggregation group corresponding to the service traffic (102); forwarding the service traffic, according to a local strategy, to a peer device via a pseudo wire in “forwarding” or “active” status in the pseudo wire aggression group, the pseudo wire aggregation group including more than one pseudo wire corresponding to the service traffic (103). The embodiments of the invention improve average convergence rate of the service traffic and reduce switchover time when a failure occurs in the network.

Abstract: A switch fabric for a modular router may be tested without connecting the switch fabric portion of the router to the other modular portions of the router. The switch fabric may generate test data units and insert the test data units into one or more elements of the switch fabric. The switch fabric may operate with the inserted test data units. A control component may receive data units from the switch fabric after operation of the switch fabric and analyze the received data units to determine whether the received data units correspond to the inserted test data units.

Abstract: A system and method for squelching a recovered clock in an Ethernet network. In one embodiment the invention provides a method for squelching a recovered clock in an Ethernet network comprising a local node coupled to a remote node by a link, the method including receiving a descrambler status signal, receiving a remote receiver status signal, receiving a link status signal, and squelching the recovered clock signal based on the descrambler status signal, the remote receiver status signal, and the link status signal.

Abstract: A disclosed example method to identify a failure in a logical circuit involves receiving non-requested trap data from a plurality of switches forming a logical circuit. The logical circuit spans first, second, and third logical networks. The example method also involves polling first and second switches of the logical circuit exclusive of others of the plurality of switches of the logical circuit. The first switch forms a first network-to-network interface between the first logical network and the second logical network. The second switch forms a second network-to-network interface between the second logical network and the third logical network. The first and second switches are selected for polling based on the trap data indicating a problem at the first and second switches. The example method also involves identifying a failure of the logical circuit without manual intervention based on the polling.

Abstract: A transmission system includes a transmission device and a reception device connected with each other via two lines. When the transmission device switches a line, used for transmitting VLAN traffic, from a first line to a second line, the transmission device transmits the VLAN traffic to the second line by switching the line after transmitting a post-switching message to the first line. The reception device includes a first buffer which stores the VLAN traffic received from the first line and a second buffer which stores the VLAN traffic received from the second line. When the reception device receives the post-switching message from the first line, the reception device starts reading of the VLAN traffic from the second buffer after reading the entire VLAN traffic stored in the first buffer.

Abstract: A gateway is used to segment a network, such as a FAULT TOLERANT ETHERNET (FTE) network, into islands. The gateway receives traffic from a first island, forwards part of the traffic to a second island, and blocks another part of the traffic from being forwarded to the second island. The forwarded traffic could include unicast traffic. The blocked traffic could include broadcast or multicast traffic, including diagnostic messages from one or more nodes in the first island.

Abstract: A method for managing a plurality of subscriber sessions tied to mobile devices in a router, each subscriber session of the plurality of subscriber sessions assigned to a line card in the router, the line card implementing a data plane entity and a control card implementing a control plane entity, the method comprising: redistributing each subscriber session in the plurality of subscriber sessions assigned to a failed line card in the router to minimize packets lost and maximize subscriber session retention, redistributing including classifying each subscriber session in the plurality of subscriber sessions into a plurality of priority queues, in response to detection of the failed line card, transferring each subscriber session in the plurality of subscriber sessions assigned to the failed line card to one of a plurality of operating line cards in priority queue order.

Abstract: Methods and apparatus for efficiently allowing protection switch information to be communicated on bidirectional lines are disclosed. According to one aspect of the present invention, a method for communicating protection switch information from a first network element to a second network element across bidirectional links that include at least one working line and a protection line involves obtaining a generic framing procedure GFP frame at the first network element. The GFP frame has a payload area with a client payload field. The method also includes defining a command field associated with the GFP frame that is in the payload area but not in the client payload field, and storing protection switch information in the command field.

Abstract: Methods and systems are provided for automatically rerouting data. In accordance with a disclosed example method, congestion is identified in a logical circuit. The logical circuit comprises at least a first communication path in a first local access and transport area, a second communication path in an inter-exchange carrier, and a third communication path in a second local access and transport area. The example method also involves determining that the congestion is isolated to the second communication path in the inter-exchange carrier. Data associated with the logical circuit is rerouted without manual intervention using an alternate communication path to bypass the inter-exchange carrier. The rerouting comprises routing the data through the first local access and transport area, the alternate communication path, and the second local access and transport area.

Abstract: A network element disposed at an edge of a connectivity fault management (CFM) domain includes a switch fabric, a central processor (CP) card, and a line card in communication with the CP card through the switch fabric. The line card includes an Ethernet interface for transmitting and receiving Ethernet CFM frames over a network and circuitry configured to generate new continuity check messages (CCMs) periodically, to process CCMs received on each connection supported by the line card, and to detect a loss of continuity for any of the connections supported by the line card. The line card maintains a list of supported connections. A generate timer and an age counter are associated with each connection in the list. The line card generates a CCM for a given connection when the generate timer expires and detects a loss of continuity for the given connection when its age counter exceeds a threshold.

Abstract: A technique is provided for dynamically discovering shared risk node group (SRNG) memberships of a plurality of interconnected edge devices in a computer network. According to the technique, each edge device “learns” the identities of its directly-attached peer devices situated in neighboring routing domains, e.g., by establishing an interior or exterior gateway routing protocol session with each peer. Thereafter, each edge device advertises the identities of its learned peers to the other interconnected edge devices. Preferably, the peer identities are distributed in novel “peer-router” extended community attributes transported in Border Gateway Protocol (BGP) messages. After an edge device has learned the identity of its own peers and received the identities of the other edge devices' peers, the device can automatically detect SRNG memberships in the computer network. Specifically, edge devices that advertise the same peer are determined to participate in the same SRNG.

Abstract: Systems and methods for routing protocols for power line communications (PLC) are described. In some embodiments, a method may include transmitting a one-hop broadcast request message to a plurality of PLC devices in a mesh network and receiving a response from each of the devices. The method may also include selecting one of the devices as a bootstrapping agent, sending a join request to a bootstrapping server through the bootstrapping agent, and, in response to successfully joining the network, setting the bootstrapping agent as a next hop toward a bootstrapping server. In another embodiment, a method may include maintaining a routing table for a plurality of PLC devices in a mesh network, receiving a join request from a PLC device, accepting the request, and updating the table to add a record corresponding to the PLC device; the record setting the bootstrapping agent as a penultimate hop toward the PLC device.

Abstract: Systems and methods are provided for processing Time Domain Multiplexing Pilot symbols by employing complex accumulators to determine peak values which indicate the start of timing and frequency information. In an embodiment, a method is provided for timing acquisition in a wireless network. The method includes acquiring samples from an Orthogonal Frequency Division Multiplexing (OFDM) data packet over a predetermined period of time, where the samples include one or more TDM pilot symbols. The samples are then processed to determine a maximum value that indicates the TDM pilot symbol has been detected.

Abstract: A method and system are provided for prioritized rerouting of logical circuit data in a data network. A logical circuit failure is identified in the data network. Following the identification of the logical circuit failure, a quality of service parameter for the communication of data in the failed logical circuit is determined. The quality of service parameter may include a traffic descriptor indicating the quality of the data communicated in the logical circuit. Then, a logical failover circuit comprising an alternate communication path for communicating the data in the failed logical circuit is identified. Next, a quality of service parameter for the communication of data in the logical failover circuit is determined. If the quality of service parameter for the failed logical circuit is equal to the quality of service parameter for the logical failover circuit, then the data from the failed logical circuit is rerouted to the logical failover circuit.

Abstract: A system, method, and device for monitoring the connectivity of a network that has been configured in a ring topology, such as an Ethernet ring network. The ring network includes a plurality of nodes, each with first port and a second port for forwarding CC messages to respective neighbor nodes, and an MEP for forming and processing the CC messages. Of the plurality of network nodes, neighbor nodes are selected as CC forwarding nodes and, after a database on each node has been configured, the selected nodes begin sending CC messages to each other via the ring network, beginning with transmission to a non-selected node. If a selected node fails to receive an expected CC message, it transmits a fault notification and ceases sending CC messages. The network then reselects CC message forwarding nodes, which begin forwarding CC messages until another fault is detected or the network is otherwise reconfigured.

Abstract: The invention provides a method and switching device for configuring stack ports. A switching device in a stacking system searches in the neighbor information table to determine whether the neighbor ID carried in a stack link negotiation packet is contained in the table after it receives the stack link negotiation packet on one of its physical ports that is enabled with the stacking function. If the neighbor ID is contained in the table, the switching device adds the physical port to the stack port corresponding to the neighbor ID in the neighbor information table; if it is not contained in the table, the switching device creates a stack port not in use, creates a binding between the neighbor ID and the stack port, and adds the physical port to the stack port. The present invention can automatically configure stack ports, greatly reducing the configuration work of administrators, and avoiding stacking device faults caused by manual configuration errors at the same time.

Abstract: The present invention discloses a method for diagnosing a physical downlink failure so as to solve the problem in the existing technology of being unable to report information accurately when the physical downlink failure occurs thereby influencing the diagnosis of the physical downlink failure. The method comprises: when a remote device detects the physical downlink failure, determining a code corresponding to information required to be reported based on a stored corresponding relationship between the information and the code; the remote device generating a control signal from the determined code based on an appointed frequency clock; and the remote device reporting a signal corresponding to the control signal to a near-end device through a physical uplink such that the near-end device diagnoses the physical downlink failure according to the reported signal.

Abstract: The invention relates to a method and a simulator (1) for identifying and/or tapping a mobile terminal (7) in a digital cellular mobile radio network, in which data is transmitted according to a code multiplex method. The aim of the invention is to enable a terminal (7) to be identified in a mobile radio network, in which data is transmitted according to a code multiplex method and if required to enable the tapping of conversations that are conducted via the mobile telephone.

Abstract: In a digital wireless communication device having an error correction function, the circuit quality is quickly detected with maintained accuracy. The circuit quality to such an extent that a bit error rate (BER) is slightly degraded (10?10 to 10?12) is quickly detected with maintained accuracy by monitoring the circuit quality based on a C/N error pulse into which C/N information scaling a carrier-to-noise power ratio (C/N) of a received signal has been converted.

Abstract: A system for maintaining routing capabilities in a router having a failed control plane provides an active control plane in the router in communication with at least one external node, the active control plane running at least one routing process. A backup control plane may be interconnected with the active control plane, so that the active control plane may periodically transmit synchronization signals to the backup control plane. The backup control plane may update its state based on these synchronization signals. Moreover, the backup control plane may be programmed to take over the routing process of the active control plane if the active control plane fails.

Abstract: Described is a rack-switch including a rack and a plurality of blade server chassis within the rack. Each blade server chassis has a plurality of server blades in communication with at least one switch. Each switch includes a plurality of external ports. At least two of the external ports of each switch are inter-switch link (ISL) ports. The rack-switch also includes a plurality of inter-switch links. Each inter-switch link electrically connects one ISL port of one of the switches to one ISL port of another of the switches. The plurality of inter-switch links interconnects the switches such that the switches are daisy chained in a loop. The inter-switch links convey Ethernet packets representing server-to-server communications between server blades of different blade server chassis.

Abstract: The disclosure discloses a method, a system and a signaling gateway for enabling message intercommunication between a Global System for Mobile Communications (GSM) network and a Code Division Multiple Access (CDMA) network. The method comprises: setting a GSM-CDMA (GC) signaling gateway in a service processor of a CDMA short message service center; during processing a message from the GSM network to the CDMA network, a GSM short message service center sending a mobile terminated request message to the GC signaling gateway, and the GC signaling gateway converting a GSM message into a CDMA message according to the mobile terminated request message and sending the converted CDMA message to a target CDMA subscriber; and, during processing a message from the CDMA network to the GSM network, a CDMA service processor converting a CDMA message into a GSM message and sending the converted GSM message to a target GSM subscriber.

Abstract: The present invention discloses a method for detection of Ethernet segment protection, and this method includes: configuring a detection point in two segment protection domains with a shared link; configuring a joint monitor group on the shared link of said two segment protection domains; and judging whether the configured detection point and the joint monitor group receive a Continuity Check Message (CCM) in a certain period, if the CCM message is received, determining a detected segment corresponding to this CCM message is normal; if the CCM message is not received, determining the detected segment corresponding to this CCM message has a fault. The present invention further discloses a system for detection of Ethernet segment protection, including: a detection point configuration unit, a joint monitor group configuration unit and a judgment unit.

Abstract: Methods and apparatus are disclosed for detecting ground faults in an Ethernet system. An Ethernet switch is configured to provide inline power to a plurality of ports each having positive and negative rails. Current is injected into selected rails of a port and ground isolation is temporarily broken for the port. A detected mismatch in current levels between the positive and negative rails of the port indicates a ground fault in the port.

Abstract: The method involves issuing, by an active interface, an Internet Protocol probe packet (IPPP) to a probe target, issuing, by a first alternate interface, a first transitive probe packet (TPP) to the active interface, where the first alternate interface and the active interface belong to a broadcast domain. The method further involves awaiting, by the active interface, a responsive IPPP from the probe target, awaiting, by the first alternate interface, a first responsive TPP from the active interface, and determining network conditions based upon receiving at least one of the responsive IPPP and the first responsive TPP.

Abstract: At least one substitute path is provided in place of a plurality of existing paths of a network to reallocate traffic carried by the plurality of existing paths. The total bandwidth needed to carry the traffic of the plurality of existing paths is determined. A proposed route is generated from the available links in the network. A portion of the bandwidth of a proposed route may be allocated to the needed bandwidth when the bandwidth of a proposed route is greater than or equal to the needed bandwidth. When the bandwidth of the proposed route is less than the needed bandwidth, at least one further route is generated, and the needed bandwidth is divided among the proposed route and the at least one further route such that a minimum number of further routes are generated.

Abstract: Techniques are disclosed for in-band communication of alarm status information or other information between physical layer devices comprising a working device and a protection device in a network-based communication system. In one aspect, a protection receive signal is monitored in the protection device for the presence of alarm status information. The protection device encodes alarm status information extracted from the protection receive signal, and inserts the encoded alarm status information into one or more designated portions of a protection loop-back signal supplied from the protection device to the working device. The protection loop-back signal is monitored in the working device and the encoded alarm status information therein is decoded and utilized by the working device to initiate a protection switching operation.

Abstract: In a network (10) providing a service to a client of a terminal (T1) and comprising at lease first and second session border controllers (A, B), at least one identical address (@Ain) is allocated to the first and second session border controllers. A router (Ra) connects the terminal (T1) to the first session border controller (A) and is capable of dynamically managing a routing table indicating at least first and second routes for the address. A message transmitted from the terminal to the network is received at the first session border controller when the router selects the first route and at the second session border controller when the router selects the second route.

Abstract: A method, system and device are disclosed for compensating or tuning one or more communication pathways between an external network and an information handling system. In one aspect, one or more inductive devices may be coupled to one or more transmission lines coupling a physical layer transceiver (PHY) to one of a plurality of external network communication ports via a board-mounted communication switch. Selection and placement, such as serial placement, of the one or more inductive devices depends, at least in part, upon one or more electrical characteristics of the transmission lines, the PHY, the communication switch and requirements of the external network.

Abstract: A method performed by a network device may include establishing performance-based Bidirectional Forwarding Detection (BFD) sessions for each link of a primary traffic engineering Label Switched Path (TE-LSP) and establishing performance-based BFD sessions for each link of a secondary TE-LSP. The method may also include, monitoring performance of the primary TE-LSP based on the performance-based BFD sessions for each link of the primary TE-LSP and monitoring performance of the secondary TE-LSP based on the performance-based BFD sessions for each link of the secondary TE-LSP. The method may further include determining that the performance of the primary TE-LSP is degraded based on the monitoring of the performance of the primary TE-LSP and automatically switching a flow of data unit traffic from the primary TE-LSP to the secondary TE-LSP when the performance of the primary TE-LSP is degraded.

Abstract: The invention discloses a method for implementing dual-homing, including: setting each one of any two core control equipment as a standby for each other, connecting a network entity belonging to one of the core control equipment with the two core control equipment through a primary link and a standby link respectively; setting the primary link connected with the core control equipment as activated, and setting the standby link connected with the core control equipment inactive; determining whether the core control equipment corresponding to the primary link is out of service, if the core control equipment corresponding to the primary link is out of service, activating the standby link; otherwise, continuously determining whether the core control equipment corresponding to the primary link is out of service. The invention also discloses another method for implementing dual-homing, by which the reliability of the network can be improved.

Abstract: A method of transmitting data over a communication network using negative acknowledgment is presented. In the method, a stream of data packets is transmitted from a first node of the network to a second node of the network. All but at least two of the stream of data packets is successfully received at the second node, wherein the data packets that are not successfully received are not located sequentially within the stream of data packets. A status packet is transmitted from the second node to the first node, wherein the status packet includes an indication of each of the data packets that were not successfully received. In response to receiving the status packet at the first node, the data packets that were not successfully received at the second node are retransmitted from the first node to the second node in response to receiving the status packet.

Abstract: A communication system having a wireless trunk for connecting multiple phone lines over wireless communication links to a cellular network comprises a central telephone switch, such as a private branch exchange or key system, connected through one or more trunk lines to a wireless access communication unit. The wireless access communication unit preferably comprises a separate subscriber interface for each trunk line from the central telephone switch. The wireless access communication unit collects data from each of the subscriber interfaces, formats the data into a format compatible with an over-the-air protocol, and transmits the information over one or more wireless channels to a cellular base station. The wireless access communication unit thereby connects calls received from the central telephone switch's trunk lines over a wireless trunk to a network.