Abstract: Methods and apparatus for mitigating denial of service attacks in a communications network are described. Frequency domain techniques such as Fourier Transform are used to detect packet flooding in which a frequency spectrum reveals a periodic pattern to the attack packets. A pulse generator is used to create pulses having the frequency and phase of the periodic pattern. New packets arriving simultaneously with the created pulses are dropped from the system and packets which are not synchronized with the pulse generator are passed through the system normally.

Abstract: A multi-protocol switch that supports both ATM and IP traffic and method for use is presented. The multi-protocol switch associates certain input connections, as identified by virtual path identifier/virtual connection identifier (VPI/VCI), with either IP or ATM traffic. When the connection identifier for a cell received indicates that the cell is an ATM cell, the multi-protocol switch forwards the cell through the switch, where the forwarding is based on the connection identifier for the cell. If the connection identifier for a cell indicates that the cell is IP traffic, the cell is stored with other cells included in the IP packet to which the cells correspond within the ingress line card of the switch. The destination address included in the packet is used to determine a forwarding decision for the cells included in the packet. After at least partial reassembly, the packet is segmented and forwarded through the switch based on the forwarding decision determined from the destination address.

Abstract: The solution provides automated Command Line Interface (CLI) based configuration management of managed communications network entities. The automation eliminates manual CLI command entry and provides support for independently-developed multi-vendor equipment by using multiple CLI command vocabularies and CLI command dictionaries associated therewith. The solution reduces communications network entity management costs, downtime, and training time for analysts. The advantages are derived from a generic design of software applications and a manageable object type derivation hierarchy, reducing operational over heads by shielding thereof from updates to the CLI command grammar and/or vocabulary. The methods and apparatus presented herein remove the need for software applications and manageable object type derivation hierarchy to be hard-coded with knowledge of attribute dependencies of CLI commands for each vendor equipment/type supported.

Abstract: A policing technique for a telecommunications traffic of variable length packets is described. The technique uses a plurality of police engines, grouped in pairs. A selection module selects a police engine pair to process a packet. Each police engine contains a conformance unit, credit unit and a debit unit, in which the credit update of one police engine influences the credit update of the other police engine in the pair. The technique also uses a combinatorial function to decide on a category of a processed packet and which police engines to update their debit units.

Abstract: A bridged virtual LAN (VLAN) has a number of segments connected by a connection-based network such as an ATM network. Multicast data originating in a first one of the segments is carried to two or more other segments by a point-to-multipoint virtual channel configured in the connection-based network. A separate point-to-point virtual channel may be provided for other data and bidirectional control signals. The segments may be ethernet segments with data flow over the point-to-multipoint virtual channel being unidirectional. Ethernet frames may be carried by a protocol such as AAL5.

Abstract: A source selection system for a communication switch for selecting a primary datasource from a plurality of datasources is provided. The system includes a validation module associated with the plurality of datasources adapted to monitor each datasource of the plurality of datasources for transmission errors in output originating from each datasource and adapted to provide information relating to the transmission errors. The system also includes a source selector associated with the validation module and the plurality of datasources, the source selector adapted to select an output datasource from the plurality of datasources. The system further includes an assessment module associated with the validation module adapted to identify the primary datasource from the plurality of datasources utilizing the information provided by the validation module and adapted to cause the source selector to select the output datasource associated with the primary datasource.

Abstract: A method of re-establishing a connection for a communication link is provided. The link has first and second portions, having the first portion in a first communication network, the second in a second communication network and an interface connecting first portion to the portion. The first communication network has a first communication protocol and a first OAM protocol to monitor integrity of the first portion. Similarly, the second communication network has a second communication protocol and a second OAM protocol. The method utilizes the second OAM protocol to detect a failure in the second portion. Upon detection of the failure, an alternate route for the second portion in the second communication network is identified, where the alternate route is able to complete the second portion of the communication link from the interface. For the communication link, at the interface the second portion is replaced with the alternate route.

Abstract: A bridge for interconnecting a processor to a peripheral device by way of a PCI bus may have a read buffer. The bridge autonomously requests data from the peripheral device and places received data in the read buffer. The processor reads the data from the receive buffer. The bridge may have a write buffer. The bridge accumulates data in the write buffer until a triggering event occurs. Upon the occurrence of a triggering event the bridge sends the data in the receive buffer to the peripheral device in a burst.

Abstract: A method and system for detecting and controlling congestion in a multi-port shared memory switch in a communications network. The proposed congestion management scheme implements a local and a global congestion monitoring process. The local monitoring process monitors the queue depth. When the queue depth for any queue exceeds a queue length threshold a congestion control mechanism is implemented to limit incoming data traffic destined for that queue. Additionally, the global congestion monitoring process monitors the shared memory buffer and if the traffic thereto exceeds a shared memory buffer threshold a congestion control mechanism limits incoming traffic destined for any output queue which has been exceeding a fair share threshold value.

Abstract: Methods and components for processing Universal Resource Locator (URL) requests for web content are presented. The application servers and/or application software implement request switching components adapted to route URL requests for web content to servlets adapted to perform modularized functionality in servicing URL requests. The combination of request switch and servlet components define a request processing network. The advantages are derived from a flexibility in adding, modifying, and removing servlets from the request processing network at reduced regression testing. Each URL request is optimally routed only to necessary components to service the request. The use of request switches consolidates and simplifies the servlet triggering functionality in selecting servlets to service each URL request enabling specialized processing of URL requests. Solutions using servlet network arrangements enable parallel processing of URL requests.

Abstract: A method of interacting with a managed data network entity is provided. The method includes a sequence of steps. A change in the operational state of the managed data network entity is detected. A CLI dictionary entry is retrieved form a CLI dictionary associated with the data network entity. Based on the retrieved CLI dictionary entry, CLI commands are extracted therefrom to configure the managed data network entity to reflect the detected change in the operational state. A CLI command sequence is built from the extracted CLI commands. Each CLI command in the command sequence is sent to the managed data network entity for execution. CLI command responses are monitored. Based on a successful execution of CLI commands send, subsequent CLI commands in the CLI command sequence are sent for execution. The solution provides automated configuration management of data network entities from different vendors when SNMP is not a viable option.

Abstract: A network management and administration system provisioning data links in an optical networking environment is provided. The network management and administration system makes use of connectivity information in establishing and monitoring data links. The connectivity information includes data link termination specifications. Data link termination specifications include port and channel specifications. Each port may have a channelized or an unchannelized configuration. A virtual channel having a data transport capacity substantially equal to that of a corresponding unchannelized port is defined therefor. The advantages include a standardized, concise and comprehensive provisioning and presentation of data links.

Abstract: A method of interacting with a managed data network entity is provided. The method includes a sequence of steps. A change in the operational state of the managed data network entity is detected. A CLI dictionary entry is retrieved form a CLI dictionary associated with the data network entity. Based on the retrieved CLI dictionary entry, CLI commands are extracted therefrom to configure the managed data network entity to reflect the detected change in the operational state. A CLI command sequence is built from the extracted CLI commands. Each CLI command in the command sequence is sent to the managed data network entity for execution. CLI command responses are monitored. Based on a successful execution of CLI commands send, subsequent CLI commands in the CLI command sequence are sent for execution. The solution provides automated configuration management of data network entities from different vendors when SNMP is not a viable option.

Abstract: Methods of detecting TCP SYN flooding attacks at a router located between a LAN and a network such as the Internet are described. The methods rely on a counting arrangement in which SYN and Fin packets are counted on both the LAN side and the network or Internet side of the router during a time interval. Weighting factors are applied to each count, the factor for the LAN side count having the opposite polarity to the factor for the network side count. The absolute values of the sums of the weighting factors of like polarity are equal. An abnormal number of unsuccessful connection attempts are determined based on a parameter calculated using the weighting factors in conjunction with the respective counts.

Abstract: An optical network unit having an environmentally sealed printed circuit board arrangement within a first compartment and a signal in/out arrangement in a second compartment. The compartments are provided by two housings. Instead of replacing individual circuit boards in the case of breakdown or malfunction, replacement of the whole of the printed circuit board arrangement is necessary thereby eliminating human error and minimizing downtime. Two housings provide the two compartments. These housings are preferably mounted upon a housing mount and a carrier for the optical network unit is also preferably mounted upon the housing mount. This housing and carrier arrangement simplifies assembly and disassembly of parts of the unit for maintenance and replacement purposes.

Abstract: An optical network unit having an environmentally sealed printed circuit board arrangement within a first compartment and a signal in/out arrangement in a second compartment. The compartments are provided by two housings. Instead of replacing individual circuit boards in the case of breakdown or malfunction, replacement of the whole of the printed circuit board arrangement is necessary thereby eliminating human error and minimizing downtime. Two housings provide the two compartments. These housings are preferably mounted upon a housing mount and a carrier for the optical network unit is also preferably mounted upon the housing mount. This housing and carrier arrangement simplifies assembly and disassembly of parts of the unit for maintenance and replacement purposes.

Abstract: Disclosed is a system for providing redundancy on a communications switch platform having a data plane for processing data. The data plane includes an active fabric having an ingress and an egress and establishing a first datapath, a redundant fabric having an ingress and an egress and establishing a second datapath, and a fabric switch for aligning the egress of one of said fabrics to a system output. A separate and independent control plane is provided for monitoring the processing of data. The control plane includes: (i) a plurality of monitors operatively connected to monitor the status of the active and redundant fabrics in the data plane for a fault; and (ii) a fabric activity switch circuit adapted to determine whether the fault occurred in the active fabric in the data plane, and if so, to generate a fabric activity switch signal directed to said fabric switch in the data plane.

Abstract: A single shelf network system capable of providing expansion to a multiple shelf mode is described. In one embodiment, slots are provided in a single shelf network system that are capable of accepting either I/O cards or expansion cards. When such a single shelf network system is to be operated in a single shelf mode, such slots may be provided with I/O cards to maximize the data transport capability of the single shelf network system. However, to expand the single shelf network system to function as a multiple shelf network system, the slots are provided with expansion cards. The expansion cards serve to couple a control card of the single shelf network system to one or more expansion shelves, thereby allowing the control card to exert control over the one or more expansion shelves. Since a single expansion card can support multiple expansion shelves, the number of slots of the single shelf network system needed to support expansion does not increase as additional expansion shelves are added.

Abstract: A connection system for a communication switch is provided. The switch comprises a controller and shelves providing communication capabilities for the switch. The controller is able to communicate with each shelf shelves utilizing categories of communication signals. The connection system comprises connections providing signalling links for the categories of communication signals between the controller and the each shelf. The connections are bundled together in a single, collective span of cable and each connection provides its individual category communication signals independently of the other connections.

Abstract: A system and method of notifying a first communication network of a fault related to a second communication network is provided. The first communication network is connected to the second communication network. The first communication network has a first OAM protocol adapted to monitor integrity of the first communication network and the second communication network has a second OAM protocol adapted to monitor integrity of the second communication network. The method includes detecting the fault related to the second communication network and generating a first OAM cell of the first OAM protocol indicating detection of the fault. The method further includes transmitting the first OAM cell to the first communication network to indicate the fault to the first communication network.