A security infrastructure and methods are presented that inhibit the ability of a malicious node from disrupting the normal operations of a peer-to-peer network. The methods of the invention allow both secure and insecure identities to be used by nodes by making them self-verifying. When necessary or opportunistic, ID ownership is validated by piggybacking the validation on existing messages. The probability of connecting initially to a malicious node is reduced by randomly selecting to which node to connect. Further, information from malicious nodes is identified and can be disregarded by maintaining information about prior communications that will require a future response. Denial of service attacks are inhibited by allowing the node to disregard requests when its resource utilization exceeds a predetermined limit. The ability for a malicious node to remove a valid node is reduced by requiring that revocation certificates be signed by the node to be removed.

Peer-to-peer name resolution protocol (PNRP) security infrastructure and method

A communications network has a plurality of nodes interconnected by an optical transmission medium. The transmission medium is capable of a carrying a plurality of wavelengths organized into bands. A filter at each node for drops a band associated therewith and passively forwards other bands through the transmission medium. A device is provided at each node for adding a band to the transmission medium. Communication can be established directly between a pair of nodes in the network sharing a common band without the active intervention of any intervening node. This allows the network to be protocol independent. Also, the low losses incurred by the passive filters permit relatively long path lengths without optical amplification.

WDM optical network with passive pass-through at each node

In a ring topology network, a number of nodes interconnect transmission links to form first and second working rings and first and second optical protection rings in a ring topology. Multiple working paths are established on each working ring and multiple protection paths are established on each protection ring corresponding to the working paths. A first working path spans across first and second nodes for transmission of a signal in a first direction of the ring topology, and a second working path of the second working ring spans across the first and second nodes for transmission of a signal in a second direction of the ring topology opposite to the first direction. A first protection path on the first protection ring spans across the first and second nodes for transmission of a signal in the second direction of the ring topology, and a second protection path of the second protection ring spans across the first and second nodes for transmission of a signal in the first direction of the ring topology. The first and second nodes normally use the first and second working paths, respectively. Responsive to a failure of one of the first and second working paths, the first and second nodes use a corresponding one of the first and second protection paths, instead of the failed working path.

Ring network for sharing protection resource by working communication paths

Techniques for provisioning single or multistage networks using Ethernet Service Instances (ESIs). In one embodiment, an ESI is a logical entity or object that stores information that may be used to provision a network. An ESI may represent a logical entity that identifies a grouping of elements of a network or network device and associated attributes. Hierarchical relationships may be created between ESIs. The hierarchical relationships are used to perform packet-level processing including performing network packet encapsulations.

PROVISIONING SINGLE OR MULTISTAGE NETWORKS USING ETHERNET SERVICE INSTANCES (ESIs)

Systems and methods for optical path protection for distributed antenna systems are provided. In one embodiment, a method is provided. The method comprises receiving an electrical uplink radio frequency signal; generating an uplink optical signal derived from the electrical uplink radio frequency signal; splitting the uplink optical signal for transmission on a primary uplink optical fiber and a secondary uplink optical fiber; combining any downlink optical signal received on a primary downlink optical communication medium and any downlink optical signal received on a second downlink optical communication medium in order to output a downlink optical signal; and generating a downlink radio frequency signal derived from the downlink optical signal.

Systems and methods of optical path protection for distributed antenna systems

Techniques for providing normal operation and service restoration capability in the event of failure of terminal equipment or transmission media in a heterogeneous network, such as a hybrid network containing single- and multi-wavelength lightwave communications systems. An optical switching node (OSN) is placed at each node in the ring network to provide the required connections between various fibers and terminal equipment, but having switch states that allow signals on the protection fibers to bypass the terminal equipment at that node. Ring-switched signals propagate around the ring on protection fibers without encountering the terminal equipment at the intervening nodes. To the extent that the protection fiber links between any given pair of nodes are incapable of supporting all the relevant communication regimes, such links are modified to provide such support.

Method and apparatus for operation, protection, and restoration of heterogeneous optical communication networks

A system for re-routing signals from an affected optical path in an optical network comprising: a first node to generate a message upon detecting a condition indicating that the signals from the affected optical path need to be re-routed via a protection path to the first node to, upon generating the message, reserve a wavelength in the protection path, the wavelenght corresponds to the signals from the afected optical path so as to allow the signals from the afected optical path to be re-routed via the protection path, at least one intermediate node to transmit and receive the message and a second node to receive that message from the at least one intermediate node and reserve the wavelenght in the protection path based on the information provided in the message. Upon receiving the message, the second node generates an acknowledgement message that is transmitted via the intermediate node to the first node.

Method and system for a bi-directional path switched network

A network element (NE) in a communications network decodes a data stream received over a communication link Upon synchronization with the data stream, the NE determines a performance metric for the link based on a number of transmission code violations In response to the performance metric exceeding a predetermined threshold, the NE commands the selection of a different link to carry the data stream via a switch signal The switching or rerouting of signals may occur between a single pair of NEs (eg, point-to-point span) or in a more complex topology having a plurality of interconnected NEs

Network performance monitoring and restoration based on transmission code violations

In a ring having first and second adjacent nodes, and two fibers carrying information between the first and second nodes, the first fiber carries information in one direction, while the second fiber carries information in another direction. Each fiber includes wavelength capacity allocated to working and protection traffic. The working and protection wavelength capacities in the first fiber are respectively assigned to first and second disjoint sets of wavelengths, while the working and protection wavelength capacities in the second fiber are respectively assigned to the second and first disjoint sets of wavelengths.

Rohit Sharma

Papers

Method and apparatus for operation, protection, and restoration of heterogeneous optical communication networks

Method and system for a bi-directional path switched network

Network performance monitoring and restoration based on transmission code violations

Wavelength and filter arrangement for WDM networks