Abstract: Methods and apparatus for allowing a dense wave division multiplexing (DWDM) line card w to function as an add/drop multiplexer (ADM), a transponder, and a muxponder are disclosed. According to one aspect of the present invention, a line card suitable for use in a network to aggregate signals of different line rates for transport includes a first arrangement having ADM functionality, a second arrangement having transponder functionality, and a third arrangement having muxponder functionality. The line card also includes hardware that facilitates communication between the arrangements, as well as a plurality of ports arranged to receive a signal and to provide the signal to the hardware.

Abstract: According to the present invention, methods and apparatus are provided to allow efficient switching of frames for transmission between a Layer 2 Virtual Local Area Network such as a Metro Ethernet Network and an external network. Reserved inner tags are used to identify particular services. In one example, inner tags allow mapping of frames associated with a particular subnetwork onto a particular virtual circuit associated with an ATM network.

Abstract: A system for resolving address conflicts in a network. In an illustrative embodiment, the system includes an address-configuration module that is adapted to assign addresses to one or more devices. The one or more devices are connected to the network via device interfaces. An interface-monitoring module communicates with the address-configuration module. The interface-monitoring module is adapted to determine when an address conflict involving plural addresses occurs and to provide a signal in response thereto. A conflict-resolution module is adapted to selectively terminate one or more device interfaces associated with the plural addresses in response to the signal and based on the addresses and one or more predetermined precedence rules. In a more specific embodiment, the system further employs a user interface for facilitating selectively adjusting the precedence rules.

Abstract: A soft notification technique isolates address family application based errors or events occurring within a routing protocol, such as the Border Gateway Protocol (BGP), used to exchange routing information between a router and its peer router over a BGP session operating on a reliable transport. The technique apportions the session into a plurality of logical subsets, each of which is associated with an address family application (AFI/SAFI) module of a BGP protocol executing on the routers. BGP soft notification messaging is employed to allow the router to notify its peer of an isolated error condition or event associated with an AFI/SAFI module. Isolation of the error/event enables restart (“soft reset”) of only the associated AFI/SAFI module, thereby obviating the need to reset or terminate the entire BGP session and reliable transport between the router and peer. Notably, soft reset of the module occurs without disrupting services provided by other AFI/SAFI modules of the BGP protocol.

Abstract: A Voice over Packet (VoP) network includes an ingress gateway and an egress gateway for transparent transport of signaling messages between source and destination telephony switches utilizing respective source and destination telephony signaling protocols. The ingress gateway is configured for interfacing with the source telephony switch according to the source telephony signaling protocol and the egress gateway is configured for interfacing with the destination telephony switch according to the destination telephony signaling protocol. The ingress gateway and the egress gateway are configured for sharing information, based on a signaling message received by the ingress gateway from the source telephony switch, to determine a selected exchange type to be used by the ingress gateway and egress gateway in transporting the signaling message to the destination telephony switch.

Abstract: A reconfigurable WDM add/drop multiplexer and its method of operation at an add/drop node on an optical fiber carrying a plurality of WDM signals is described. The WDM add/drop multiplexer has a coupler and a demultiplexer element dropping WDM signals from the optical fiber to a plurality of drop terminals, and a wavelength-selective switch adding WDM signals from a plurality of add terminals onto the optical fiber. The coupler splits the WDM signals received from the optical fiber and passes the split WDM signals to the first and second output terminals. The demultiplexer element separates the split WDM signals at the plurality of drop terminals. The wavelength-selective switch, which has an input terminal for connection to the second coupler output terminal and an output terminal for connection to the optical fiber, selectively adds WDM signals on the plurality of add terminals to the optical fiber responsive to control signals.

Abstract: A system and technique for analyzing incoming packets. The path taken by incoming packets can be analyzed from a near end without having access to the far end. This can be done even though packets sent to the far end from the near end, take a different path than that used by the incoming packets. The process is started by an RTP no op packet sent from the near end to the far end. The no op packet request the far end to initiate a trace using a series of media packets that have sequential values in the TTL field. The results of the trace are either send from the far end to the near end and a report is complied at the near end, or the results of the trace are compiled into a report at the far end and the report is sent to the near end.

Abstract: A mobile node on a cell-based wireless network (e.g., implemented using GSM) may indicate multicast applications (provided on a data network) of interest and receive data related to the applications. A data switch connected to the data network may receive a list of multicast applications of interest in the entire wireless network, and send data related to only the applications of interest to a gateway. The gateway may interact with a switching center and base station operating in conjunction with wireless network to extend the multicast applications to mobile nodes.

Abstract: A method of providing network services is described. The network includes a number of nodes, each one of which is coupled to at least one other of the nodes by at least one of a number of optical links. The network is preferably capable of supporting a number of virtual circuits. The method begins with the receiving of a request for a virtual circuit between a first node and a second node of the network. Preferably, the request specifies a quality of service of the virtual circuit. Next, the availability of network resources for supporting a virtual circuit at the requested quality of service is determined. Assuming sufficient network resources are available for support of the virtual circuit, the request is then serviced by provisioning (and maintaining) the requested virtual circuit. Servicing the request preferably includes actions such as provisioning, maintaining, and restoring the virtual circuit, using the requested parameters.

Abstract: A method for improving a frequency utilization efficiency for a wireless communication system having a plurality of cells includes the following steps. At least one primary channel is allocated for each cell, the primary channel being different from that of its neighboring cell. One or more secondary channels are allocated for each cell, which have the same frequencies as their corresponding primary channels but differ in configuration, the secondary channels being different in frequency from the primary channel of the same cell. The secondary channel of the cell is activated for carrying communication traffic when the primary channel of the same cell has a capacity of being used exceeding a predetermined threshold value.

Abstract: Methods and apparatus for performing optimizations for a mobile network device such as a Mobile Node or Mobile Router supporting multiple links to a Home Agent (or Correspondent Node in a Mobile IPv6 environment) are disclosed. During the registration process, link characteristics are transmitted in the registration request. From the link characteristics, it is possible to determine whether the mobile network device has roamed from a high to a low bandwidth link, or vice versa. A first set of optimizations may be performed when the mobile network device has roamed from a high to a low bandwidth link, while a second set of optimizations may be performed when the mobile network device has roamed from a low to a high bandwidth link. Some optimizations may be performed during the establishment of a TCP session, while others may be performed during or upon completion of the Mobile IP registration process.

Abstract: A fast reroute (FRR) technique is implemented at the edge of a network. In accordance with the technique, if an edge device detects a node or link failure that prevents it from communicating with a neighboring routing domain, the edge device reroutes at least some data packets addressed to that domain to a backup edge device which, in turn, forwards the packets to the neighboring domain. The rerouted packets are designated as being “protected” (i.e., rerouted) data packets before they are forwarded to the backup edge device. To differentiate which data packets are protected and which are not, the backup edge device employs different sets of VPN label values for protected and non-protected network traffic. That is, the backup edge device may allocate two different VPN label values for at least some destination address prefixes that are reachable through the neighboring domain: a first VPN label value for FRR protected traffic and a second VPN label value for non-protected traffic.

Abstract: A system for automatically selecting communication frequencies for wireless communication devices (e.g., base unit, access point, and controller) being added to an existing wireless network. The operating frequencies, evaluated signal strength, and loads are used in determining the most suitable operating frequency. This automatic selection process eliminates the problems inherent in manual frequency selection.

Abstract: Techniques for generating cyclic redundancy check (CRC) values are provided. Bit messages that are to be transmitted to recipients are aligned to desired byte boundaries for purposes of generating CRC values, which are to be sent with the bit messages. The CRC values are rewound or adjusted back to values associated with original lengths of the bit messages before the CRC values are transmitted or forwarded with the bit messages to recipients.

Abstract: A network has network nodes for storage of respective copies of a data file. One of the network nodes has a corresponding unique locality control object for the copies of the data file. The locality control object provides authority for the one network node to control storing and modifying any of the copies of the data file. The other network nodes lacking the locality control object must obtain permission from the one network node before modifying any one of the copies of the data file. The network nodes also can negotiate for passing the locality control object from the one network node to another one of the network nodes based on determined locality attributes associated with the copies of the data file.

Abstract: An exploration technique allows a router to efficiently determine capabilities and configuration of a neighbor (peer) router. In addition, the technique enables peer routers of an adjacency to negotiate a capability “outside” of a protocol, such as a routing protocol, before a routing session is established between the routers. In this context, the term “outside” of the protocol denotes that there is no field within a protocol packet (message) implementation that can be used to negotiate the capability. Moreover, the inventive technique obviates the need to manually configure a router to support a particular capability and interoperate correctly within a network of routers that both support and are unaware of the capability.

Abstract: A method for providing interoperable communications with location information includes receiving communications from a plurality of virtual talk groups. Each virtual talk group comprises a plurality of endpoints of different communication networks. The method includes receiving from a first mobile endpoint of a first virtual talk group of the plurality of virtual talk groups a first communication. The first communication comprises a first media message and location information identifying a location of the first mobile endpoint. The method includes presenting to a user the first media message from the first mobile endpoint and the location of the first mobile endpoint.

Abstract: In one embodiment, a received data packet is delivered by a routing resource to a tunnel interface resource in response to determining that the received data packet specifies a destination address starting with a prescribed aggregation prefix. The tunnel interface resource computes a home address for a mobile router based on a second address prefix from a start of the destination address, the second address prefix within the prescribed aggregation prefix and having been assigned as reachable by the mobile router, at least a portion of the second address prefix applied to a prescribed mapping function. The tunnel interface resource determines a care-of address for reaching the mobile router based on the corresponding home address calculated by the tunnel interface resource, and encapsulates the received data packet into an encapsulated packet having a destination address field specifying the care-of address, for output of the encapsulated packet toward the mobile router.

Abstract: A network device has a network interface to allow the device to send and receive traffic across a network. The device also has a cable connection to allow the device to exchange data with at least one cable modem and a processor to associate a cable interface and cable service identifier with a cable modem; receive a packet from the cable modem; and insert a layer 2 network identifier, the identifier comprising two service provider VLAN (SP-VLAN) tags, into the packet. The processor in the network device identifies a virtual trunk interface based on the outer SP-VLAN tag and identifies the virtual private network based on the inner SP-VLAN tag.

Abstract: A network access server (NAS) provides a connection to a user in a data communications network, where the NAS is capable of communicating with a home gateway server (HGS) maintaining a pool of IP addresses for allocation to authorized users associated with the NAS. The NAS includes a first memory for storing an identification of a user, an requester for asking the HGS for an IP address on behalf of the user; and a second memory associated with the first memory for storing the IP address of the user received from the HGS.