Abstract: A processor and program for analyzing network trace with the use of data packets transmitted via a network includes: a memory section 32 for storing trace data generated from the data packets; a packet analyzing section 34 for retrieving a pair of packets belonging to the same session from the trace data to generate an order relation between nodes; an array data generating section 36 for using packet pair data and order relation data to generate and store array data used for estimating time difference of the specific time axis of each node; and a solution engine section 38 for calculating an estimated value of the time difference with the use of the array data to store the estimated value in a memory.

Abstract: A method controls access of a user to a network including a plurality of hosts coupled together through a network switch. The method includes storing in the network switch an enhanced access control list containing data related to at least one of user names, DNS names, domain names, and physical addresses. A dynamic access control list is generated from the enhanced access control list, with the dynamic access control list containing a plurality of IP addresses that restrict access of the user to the network.

Abstract: Techniques for processing an IP packet at a router that supports SS7 signaling include receiving IP routing data that associates a network link and a destination IP address for a node in a signaling network that includes a plurality of signaling nodes. When an ingress IP data packet is received, it is determined whether conditions are satisfied for locally processing an SS7 payload within the ingress IP data packet. If it is determined that conditions are satisfied for locally processing the SS7 payload, then the SS7 payload is processed locally, i.e., without sending the SS7 payload over a network link to a different node in the signaling network. If it is determined that conditions are not satisfied for locally processing the SS7 payload, then the ingress IP data packet is routed normally. These techniques allow reduced numbers of expensive STP devices and expanded routing options in a signaling network.

Abstract: Methods and apparatus are provided for monitoring traffic characteristics using intelligent line cards. Selected flows are configured for monitoring based on characteristics such as an initiator target pairing or an initiator target and logical unit (LUN) grouping. Frames such as command frames associated with selected flows are forwarded to both an output port and a switch port analyzer (SPAN).

Abstract: A packet switch appliance includes a plurality of ports. One of the plurality of ports is configured to operate as a network port connected to a packet-switching network. Another of the plurality of ports is configured to operate as a first instrument port connected to a network instrument. To filter packets, one or more packets or copies of packets received through the first network port are examined prior to the packets or copies of packets being sent out the first instrument port to determine a current state of a state-based protocol, which includes a plurality of potential states. A filter is created or modified for the first network port or the first instrument port based on the determined current state of the state-based protocol.

Abstract: A high performance computer system has a number of compute nodes interconnected by an inter-node communication network. Each compute node has a local packetized interconnect coupled to the inter-node communication network by an interface. Data packets on the local packetized interconnect of a sending node may be delivered to a destination in a receiving node by addressing them to addresses associated with the network interface and tunneling the packets through the inter-node communication network to the receiving node.

Abstract: Prior to alteration of the communication route connecting the enterprise servers 51 to 53, ports a, b and c of the enterprise server 51 are each connected with port 1 of the storage system 7 through the communication route. When enterprise server 54 is connected with the storage system 7 in response to a new connection request, the communication port of the storage system 7 with which ports a, b and c are respectively connected through the communication route is altered to port 3. Due to this alteration, the enterprise server 544 can be connected through its port f via the communication route with the port 1 of the storage system 7, which was thus freed.

Abstract: Disclosed herewith is a PON system and a bandwidth controlling method capable of controlling congestion with use of an upstream bandwidth in a PON section efficiently when congestion occurs in a gateway (GW) connected to an OLT. An OLT connected to a plurality of ONUs through a passive optical network (PON) and to a gateway (GW) through a communication line, when receiving a congestion occurrence notice indicating a congestion occurred output number from a GW, identifies the identifier of the ONU that is using a GW output line having the congestion output port number and shifts the bandwidth controlling of the PON section in a normal mode for allocating a bandwidth to each ONU normally to that in a bandwidth suppression mode for allocating a congestion time allowable bandwidth that is less than the current bandwidth to the ONU having the identified ONU identifier and a bandwidth to each of other ONUs according to its transmission queue length.

Abstract: A frame relay apparatus includes an acquisition unit for acquiring a frame from an input port connected to a first subnet, a setting unit for setting an output port corresponding to a destination of the frame acquired by the acquisition unit, an assignment unit for assigning, to the frame, a flag indicating whether the output port of the frame set by the setting unit is connected to a second subnet, and a registration unit for storing the flag assigned to the frame by the assigning unit as well as a source address of the frame acquired by the acquisition unit and a port number in a learning table for storing a correspondence between an address and the port number.

Abstract: The present disclosure is generally directed to systems and methods associated with data communications. In a particular embodiment, a method for use of multi-protocol labels switching (MPLS) encapsulation with control word communicated over a distributed computer network is disclosed. The method includes providing MPLS virtual circuit label with the control word associated with a data packet selected from one of a customer data packet and an OAM data packet, and communicating the MPLS packet with control word and the data packet over the distributed computer network. In another embodiment, a method of handling a data packet within a computer network is disclosed. The data packet is either an unknown unicast, multicast, or broadcast packet. The method includes encapsulating the packet into a multi-packet label switching label and a control word, the control word having a source site identity and a multi-cast identity; and distributing the packet to a plurality of sites within the computer network.

Abstract: A method includes receiving on a first switching device a message from a second switching device that indicates to slow packet transmission to the second switching device.

Abstract: A method for Layer 2 packet transmission is disclosed, where a corresponding relationship between packet attribute information and public MAC addresses is configured in an access device such that the access device could find a corresponding public MAC address in the corresponding relationship when receiving a packet from a user terminal, replaces the source MAC address with the public MAC address found, and then sends the packet to a convergence layer device. A method for transmission of a Layer 2 packet without character information is also disclosed. The access device needs to obtain the packet attribute information and carry the information in the packet to be sent to the convergence layer device. An access device is also disclosed. As a result, the capacity of the VLAN and the MAC address table items needed for the convergence layer device to convert MAC addresses is greatly decreased.

Abstract: A device receives, from a customer, a request for an end-to-end path through a network, determines parameters of a query based on the request and path criteria, and executes the query on a database of network elements capable of being included in the end-to-end path. The device also selects one or more of the network elements provided in the database based on results of the query, and reserves, in the database, the one or more selected network elements for the end-to-end path.

Abstract: A network device switches variable length data units from a source to a destination in a network. An input port receives the variable length data unit and a divider divides the variable length data unit into uniform length data units for temporary storage in the network device. A distributed memory includes a plurality of physically separated memory banks addressable using a single virtual address space and an input switch streams the uniform length data units across the memory banks based on the virtual address space. The network device further includes an output switch for extracting the uniform length data units from the distributed memory by using addresses of the uniform length data units within the virtual address space. The output switch reassembles the uniform length data units to reconstruct the variable length data unit. An output port receives the variable length data unit and transfers the variable length data unit to the destination.

Abstract: The present invention relates to a method and apparatus for balancing loads in a switching fabric. The switching fabric comprises a plurality of data ports through which data frames enter or exit the switching fabric. In one embodiment, the apparatus includes a buffer and a routing data generation circuit. The buffer receives a data frame to be transmitted to a destination device via the switching fabric. The routing data generation circuit is coupled to the buffer. The routing data generation circuit generates and adds routing data to the data frame received by the buffer. The routing data identifies one of the plurality of data ports through which the data frame will exit the switching fabric to reach the destination device. After the routing data is added to the data frame, the buffer transmits the data frame to the switching system.

Abstract: A software-implemented switching path includes separate control and data planes with the data plane having a graph of feature nodes with each node implementing a feature to be applied to a packet being switched. Each feature node includes private data and code which are utilized to apply the feature to the packet. The packet is switched to a next node based on packet-specific context data.

Abstract: The present invention relates to a switching unit with a scalable and QoS aware flow control. The actual schedule rate of an egress queue, wherein the outgoing traffic belonging to a particular class of service is backlogged, is measured and compared to its expected schedule rate. If the egress queue is scheduled below expectation, then the bandwidth of every virtual ingress-to-egress pipe connecting an ingress queue, wherein the incoming traffic belonging to the same class of service is backlogged before transmission through the switch core fabric, to that egress queue is increased, thereby feeding that egress queue with more data units.

Abstract: Techniques for selecting a call completion response from a group of call completion responses based on weights associated with the call completion responses, are provided. A server processes a call invitation for a callee by forwarding the call invitation to each of the callee's endpoints. Each of the callee's endpoints associates a weight to its call completion response it generates to accept or reject the call invitation. The server waits to receive the call completion responses from each of the callee's endpoints or for a predetermined period of time (i.e., a timeout), and uses the weights associated with the received call completion responses to decide which of the received call completion responses to use to complete the call invitation.

Abstract: An apparatus and method of replacing a router in a Layer 3 network, includes configuring a new router to accept a data packet having, as a destination address field, a first media access control address of a replaced router. The method further comprises setting the destination address field of the data packet to the MAC address of the new router, and forwarding the data packet. A router performing the above method comprises configuration logic to configure the router to accept a data packet having, as a destination address, a media access control address of a replaced L3 device; and keep-alive logic adapted to periodically transmit a keep-alive packet to an allocated destination address. The router further comprises packet processing logic that accepts the received data packet, sets the destination address of the data packet to the MAC address associated with the router, and forwards the packet to a destination host.

Abstract: A distributed network access system in accordance with the present invention includes at least an external processor and a programmable access device. The programmable access device has a message interface coupled to the external processor and first and second network interfaces through which packets are communicated with a network. The programmable access device includes a packet header filter and a forwarding table that is utilized to route packets communicated between the first and second network interfaces. In response to receipt of a series of packets, the packet header filter in the programmable access device identifies messages in the series of messages upon which policy-based services are to be implemented and passes identified messages via the message interface to the external processor for processing. In response to receipt of a message, the external processor invokes service control on the message and may also invoke policy control on the message.

Abstract: Explicit signaling mechanisms facilitate automatic stitching for both packet and non-packet label switched paths (LSPs). Extensions to resource reservation protocol signaling are utilized to include explicit signaling mechanisms that setup and maintain LSPs. An inter-domain LSP may be created by automatically stitching independent LSP segments within separate domains. Stitching the intra-domain LSP segments creates an end-to-end LSP in the data plane with continuous label swapping across the different domains. An intra-domain LSP may be created by automatically stitching independent LSP segment within a single domain. A network device, such as a router, at an ingress of an LSP segment utilizes the signaling extensions to notify a network device at an egress of the LSP segment to prepare for a stitching procedure. In return, the egress network device utilizes the signaling extensions to inform the ingress network device whether the LSP segment is ready for the stitching procedure.

Abstract: A multi-slice network processor processes a packet in packet slices for transfer over a multi-port network interface such as a switch fabric. The network processor segments a packet into cells having a target size. A group of cells of a common packet form a packet slice which is independently processed by one of a number of parallel processing and storage slices. Load balancing may be used in the selection of processing slices. Furthermore, the network processor may load balance slices across the multi-port network interface to one or more destination slices of another network processor. The multi-slice processor uses post header storage delivery on ingress processing to the multi-port interface thereby reducing temporary storage requirements. The multi-slice network processor may also utilize sequence numbers associated with each packet to ensure that prior to transmission onto a destination network, the packet is in the correct order for a communication flow.

Abstract: A process of discovering a topology of devices on a network is disclosed. A discover frame is sent to nodes in communication with a central processing unit, with the discover frame having an identification list. After a response frame from the nodes is received, the response frame is processed to determine whether a node sending the response frame has an identification value. If the node has the identification value, then a routing table is updated. When the node does not have the identification value, an identification assign frame is sent to the node and an identification assign acknowledgement frame is received from the node.

Abstract: A packet routing system is provided that comprises a processor, a component, a resource map and a resource map manger. The component classifies an incoming packet of a user session. The resource map identifies a plurality of resources used to process the incoming packet. The resource map manager determines an availability of at least some of the resources and based on the availability either promote processing the incoming packet or drop the incoming packet.

Abstract: An embodiment of the invention provides a method for specifying preferred routes for SPVCs across multi-peer group PNNI networks and AINI links. A preferred route for a network connection through a network having a plurality of nodes, organized hierarchically into a plurality of peer groups, is determined. The preferred route is associated with a preferred route identifier. The preferred route identifier is carried in the PNNI SETUP message and is used to link a preferred route database in the source node with the entry border nodes of remote peer groups for a single SPVC. The entry border node of each peer group establishes a connection over a static route corresponding to the preferred route identifier. For one embodiment the preferred route identifier is carried in a generic application transport information element of the PNNI signaling SETUP message, providing a scalable preferred routing capability for SPVCs across multi-peer group PNNI networks.

Abstract: Growth of a distributed communication system is facilitated through dynamic addition of routing elements. A new routing element may be added to a network of routing elements by first establishing a connection between the new routing element and an existing routing element in the network. The connection may be either wireless or wireline. At least one address is assigned to the new routing element. Each assigned address comes from a pool of addresses maintained at the existing routing element. At least one pool of addresses is issued to the new routing element, permitting the new routing element to dynamically add yet another new routing element to the network of routing elements.

Abstract: According to an embodiment of the invention, a network device such as a router or switch provides efficient data packet handling capability. The network device includes one or more input ports for receiving data packets to be routed, as well as one or more output ports for transmitting data packets. The network device includes an integrated port controller integrated circuit for routing packets. The integrated circuit includes an interface circuit, a received packets circuit, a buffer manager circuit for receiving data packets from the received packets circuit and transmitting data packets in one or more buffers and reading data packets from the one or more buffers. The integrated circuit also includes a rate shaper counter for storing credit for a traffic class, so that the integrated circuit can support input and/or output rate shaping.

Abstract: A multiprocessor computer system comprises a sending processor node and a receiving processor node. The sending processor node is operable to send packets comprising part of a message to a receiver, to maintain a message buffer entry in the sender comprising the sent packets, to track acknowledgment from the receiver that sent packets have been received; to maintain a timer indicating the time since message data has been sent, and to resend packets not acknowledged upon the timer reaching a timeout state. The receiving processor node is operable to send acknowledgement to the sender that received packets have been received, to track packets using a received message table to track which packets comprising part of the message have been received and whether all packets in the message have been received, and to process packets once all packets in a message are received to reassemble the received message.

Abstract: A VLAN tagging method employed in a data communications switching device is disclosed. VLAN tagging is processed in accordance with one of a plurality of VLAN tagging modes, namely, a fixed port mode, a tagged port mode, a protocol-enforced port mode, a protocol-enforced port mode, and a standards-observant mode. The fixed port mode applies a VLAN tag with a default VLAN identifier associated with the ingress port. The tagged port mode preserves the tag received with the packet, or appends a new tag with a default VLAN identifier if the incoming VLAN tag is not present. In the protocol-enforced port mode, the VLAN identifier is selected based on the protocol type of the received PDU. In the standards-observant mode, an incoming VLAN tag is retained if present, or a new tag selected based on the protocol type of the received PDU if the received packet is untagged.

Abstract: Briefly, in accordance with one embodiment of the invention, a wireless communication system may adaptively switch between a multiple input, multiple output mode and a spatial division, multiple access mode based at least in part on channel conditions and traffic conditions.

Abstract: A multi-level classification scheme for classifying subscriber traffic at a network node coupled between subscribers of network services and providers of the network services includes two levels of classification. The subscriber traffic is received at the network service node. A first portion of the subscriber traffic is selectively routed from a plurality of first level routers to a plurality of second level routers within the network service node. The first portion of the subscriber traffic is then selectively routed from the second level routers to network applications executing within the network service node for processing.

Abstract: A local area network comprises a peripheral equipment effecting layer 2 switching and including physical link aggregation means, and first and second core equipments effecting layer 2 switching and including physical link aggregation means. The peripheral equipment is connected to the first and second core equipments by first and second physical links, and the first and second core equipments are connected to each other by a third physical link. The first and second core equipments also respectively comprise first and second management means each adapted to detect the presence of the core equipment in which they are not installed via the third physical link coupling them and in the event of mutual detection to instruct the transmission of a common identifier to the peripheral equipment so that it considers the first and second core equipments as a single layer 2 switch and its aggregation means aggregate the first and second physical links with the aggregation means of the first and second core equipments.

Abstract: A client-agnostic software routing component for routing input data of a type and version to a most appropriate type and version of client application of a family of related applications. The router, rather than the client application, registers as the file extension handler and as the protocol handler, and thus, receives all input data targeting the client applications. On startup, the router creates a list of available client applications, the client versions and types, and versions of input data the clients can handle. On receiving the input, the router determines if the router can parse the version of the input. The router refers to the list of available clients to determine if one or more of the client applications can handle a particular version and type of the input data. After this determination, the router routes the input to the most appropriate client.

Abstract: The present invention introduces the notions of a rendezvous component and rendezvous functionality into the communications network environment. Using the invention, an application can express information regarding when an operation requested of a device should complete and at which location, and it enables the device to perform its operations respecting this information while also improving the device's overall behavior. In an embodiment, one or more data objects are distributed across one or more collections of storage devices using a dispersal technique. When access to a data object is desired, a rendezvous component issues a set of constituent requests to the collections of storage devices. These requests typically include location and timing rendezvous parameters specifying a destination location where and a given time when a given data object is to be reconstituted.

Abstract: In a method and network for transferring data and signals between terminal equipment via one or more switching stations, the data and digitized signals are combined in cells, with each cell having a header in which connection information is contained that designates a transmission or routing target. The terminal equipment and switching stations are synchronized so that the cells are transferred in a synchronized manner via one or more switching stations. Signals and high quality of service (QoS) data thus can be transferred through the same network.

Abstract: In one embodiment, a communications distribution process maintains at least two pseudowires through a network such that the pseudowires share a burden of delivering data through the network. The communications distribution process receives feedback data concerning operation of each pseudowire. The communications distribution process utilizes the feedback data to distribute communications to the common destination across each of the pseudowires. Additionally, the communications distribution process utilizes the feedback to establish at least one new pseudowire, in addition to the first pseudowire and the second pseudowire, for transmission of data traffic.

Abstract: Automatic compilation of address filter information permits a cable modem to route incoming data packets to destination devices. A cable modem uses address filter information, such as for example, a list of addresses of communication devices that have previously registered with the cable modem, to identify incoming data packets that are addressed to communication devices associated with the cable modem. Incoming data packets with addresses that are not in the address filter information are filtered out. However, the cable modem may have insufficient filter information, when, for instance, a new communication device is associated with the cable modem. In order to automatically register communication devices associated with the cable modem, the cable modem inspects the source addresses of outgoing data packets. If the source address is not included in the address filter information, the source address is added.

Abstract: A method of operating an optical network is described. The network includes a number of nodes connected by a number of links. A method according to the present invention provisions a virtual path between a first and a second one of the plurality of nodes by: identifying the first and the second nodes, discovering a physical path from the first node to the second node, and establishing the virtual path. The method discovers a physical path from the first node to the second node by automatically identifying nodes forming the physical path. The method establishes the virtual path by configuring a set of connections between the nodes forming the physical path.

Abstract: A method for managing calls of various relative priority levels in an IP network includes polling at least one location in the network to obtain information indicative of a level of utilization said at least one location and computing a status of utilization of said at least one location based on said polled information and assigning a decision policy to said status. A priority level of a new voice call requesting to enter the network is then assessed against relative to priorities of existing calls on the network and the decision policy is invoked on the new voice call according to its relative priority level to the existing calls on the network and the decision policy in effect at the time the new voice call requests entry to the network.

Abstract: An Asynchronous Transfer Mode network (100) comprising at least one ATM node (102-106) and at least one network element (108) is disclosed. The network element is adapted to carry out signalling and routing in accordance with Private Network-Network Interface, PNNI, protocol for at least a portion of said ATM nodes. Said network element (108) is further adapted to allocate a separate time period for every one of said ATM nodes (102-106) connected to said network element (108) and to carry out said signalling and routing for every one of said connected ATM nodes (102-106) during said allocated time periods.

Abstract: A network switch for network communications includes a protocol determining means for determining whether an incoming packet is an IP packet or an IPX packet. L3 lookup tables, IP router tables, and IPX router tables are provided. A concurrent lookup is performed of the L3 lookup table, and either the IP router table or the IPX router table, depending upon the determination of the packet type. If a match is found on the L3 table, the packet is forwarded based on the L3 match. If no match is found on the L3 lookup, then a longest prefix cache lookup is performed on the appropriate IP or IPX router table, and the packet is forwarded based upon the match of the longest prefix cache lookup. If no match is provided, then the packet is forwarded to the CPU interface.

Abstract: A method and computer program product for performing minimum cost routing with network coding is presented. The method and system model a network as a directed graph. A cost per unit flow is associated with each link of the directed graph. A link capacity is associated with each link of the directed graph. A network code is then computed that sets up a routing connection that achieves an optimal cost using the cost per unit flow for each link of the directed graph and using the link capacity for each link of the directed graph.

Abstract: For transporting data packets of a data stream between a packet-oriented network (LAN) and a channel-oriented data stream processing module (VMOD), a data stream controller (ST) is provided which, via a data channel allocation module (VMUX), accesses an interface module (PS) for exchanging the data packets with the network (LAN) and/or accesses the data stream processing module (VMOD). The data stream controller (ST) transmits a data channel allocation information item (DKl1, DKl2) to the interface module (PS) and/or to the data stream processing module (VMOD). Using a data channel allocation information item (DKl1, DKl2) in each case transmitted, the data packets are transmitted directly between the interface module (PS) and the data stream processing module (VMOD), bypassing the data channel allocation module (VMUX).

Abstract: A storage network system includes computers, storage systems, connection devices that control connection relations between the computers and the storage system, and a managing device that manages the computers, the storage system and the connection devices. The managing device includes a control section that specifies connection ports of the computers, the storage system and the connection devices that compose the storage network system. Further, the control device of the managing device displays on a display section a data traffic amount at each of the connection ports for each connection path from the computer to the storage system.

Abstract: A storage network system includes computers, storage systems, connection devices that control connection relations between the computers and the storage system, and a managing device that manages the computers, the storage system and the connection devices. The managing device includes a control section that specifies connection ports of the computers, the storage system and the connection devices that compose the storage network system. Further, the control device of the managing device displays on a display section a data traffic amount at each of the connection ports for each connection path from the computer to the storage system.

Abstract: A method of routing packets in network system where the network system comprises a plurality of edge nodes and a plurality of core nodes. Selected core nodes are coupled to communicate with selected edge nodes. The network system also comprises a plurality of external nodes, with selected external nodes coupled to communicate with selected edge nodes, and where different external nodes are associated with a plurality of different entities sharing resources on the network system. The method comprises proposing a set of entities from the plurality of different entities. The proposed set comprises entities associated with external nodes that share respective connections to a number of edge nodes in the edge nodes such that the shared number is less than a total number of all edge nodes to which each different entity in the set is connected, with other aspects then taken with respect to the proposed set.

Abstract: Methods and systems for distributing messages of a ring-topology-based link level communications protocol over a star-topology using a star-topology-based link level communications protocol are disclosed. According to one method, when a packet of the ring-topology-based link level communications protocol is received, it is determined whether the packet is to be sent to a number of destinations and returned to a sender. If the packet is intended for distribution to a number of destinations and return to the sender, the packet is encapsulated in a frame of the star-topology-based link level communications protocol, the destination address in the frame is set to a next destination address in a virtual ring topology, the frame is forwarded to a switch. The switch forwards the packet to the next destination in the virtual ring based on the input port and the destination address of the star-topology-based link level communications protocol.

Abstract: Providing a corrected delivery address comprises receiving a plurality of first data elements, each of the plurality of first data elements comprising a first portion and a second portion. Next providing a corrected delivery address comprises providing a second data element, the second data element corresponding to one of the plurality of first data elements and comprising a corrected version of the second portion of the corresponding first data element. Then providing a corrected delivery address comprises receiving an indication that none of the second portions of the plurality of first data elements match the second data element and providing, in response to the indication, a link associating the second data element with the first data element corresponding to the second data element.

Abstract: A router for interconnecting external devices coupled to the router. The router comprises a switch fabric and a plurality of routing nodes coupled to the switch fabric. Each routing node is capable of transmitting data packets to, and receiving data packets from, the external devices and is further capable of transmitting data packets to, and receiving data packets from, other routing nodes via the switch fabric. The router also comprises a control processor for comparing the N most significant bits of a first subnet address associated with a first external port of a first routing node with the N most significant bits of a second subnet address associated with a second external port of the first routing node. The router determines a P-bit prefix of similar leading bits in the first and second subnet addresses and transmits the P-bit prefix to other routing nodes.

Abstract: A network switch for switching packets from a source to a destination includes a source port for receiving an incoming packet from a source, a destination port which contains a path to a destination for the packet, and a filter unit for constructing and applying a filter to selected fields of the incoming packet. The filter unit further includes filtering logic for selecting desired fields of the incoming packet and copying selected field information therefrom. The filtering logic also constructs a field value based upon the selected fields, and applies a plurality stored field masks on the field value. The switch additionally includes a rules table which contains a plurality of rules therein. The filtering logic is configured to perform lookups of the rules table in order to determine actions which must be taken based upon the result of a comparison between the field value and the stored filter masks and the rules table lookup.