Abstract: A method and apparatus for controlling multicast group subscriptions in a multicast distribution circuit is presented. When a router included in the multicast circuit receives notification to terminate support of a particular multicast group (group leave request), data flow with respect to that multicast group is initially maintained on the communication link coupling the router to the hosts. Queries are issued to hosts on the communication link to determine whether continued support of the particular group is desired by any hosts coupled to the communication link. If, while waiting for a positive response to the queries issued, a request to join an additional multicast group is received, bandwidth availability on the communication link is examined to determine if adequate bandwidth is available for supporting the newly requested group addition. If adequate bandwidth is available, the newly requested group is added to those groups supported on the communication link.

Abstract: There is provided a method and apparatus for the ordered release of connections from a network entity in a signalling communications network upon the detection of the failure of a signalling link or a port corresponding to such connections. A priority indicator is associated with each of the connections. Each priority indicator is selected from a priority hierarchy having several priority levels which varies from highest priority to lowest priority. Upon detection of the failure of a signalling link or port, every connection associated with the failed signalling link or port is released. The release of the connections takes place at the network entity in a sequence which corresponds to the priority hierarchy. A method and device are also provided for the ordered release of connections carried on a logical truck having a variable capacity, for example an IMA trunk, upon the detection of a reduction in capacity. The IMA trunk may be provided on several physical links.

Abstract: A coordinated method is provided for controlling dynamic gain equalization in an optical transport network. The method includes: detecting a deviation in optical power of an optical signal traversing the optical transport network along a transmission path, adjusting spectral profile of the optical signal at a first network element in the optical transport network, where the first network element is located in the transmission path downstream from the origination point of the deviation; and adjusting spectral profile of the optical signal at a second network element subsequent to the adjustment at the first network element, where the second network element is located in the transmission path downstream from the origination point and the first network element.

Abstract: A request method for performing optical power management to accomplish planned addition and removal of wavelengths in an optical communications system is disclosed, wherein each wavelength has a path of transmission through the system. The method comprises communicating a request for a power ramp to at least one path network component in the path, determining that the path network component has made preparations for the power ramp, and performing a power ramp in response to the determination. Further, a response method for performing power management to accomplish planned addition and removal of wavelengths in an optical communications system is disclosed, wherein each wavelength has a path of transmission through the system. The method comprises receiving a request for a power ramp, making preparations for the power ramp, determining that the power ramp has been completed, and resuming normal operation in response to the determination.

Abstract: A method and apparatus for controlling multicast group subscriptions in a multicast distribution circuit is presented. When a router included in the multicast circuit receives notification to terminate support of a particular multicast group (group leave request), data flow with respect to that multicast group is initially maintained on the communication link coupling the router to the hosts. Queries are issued to hosts on the communication link to determine whether continued support of the particular group is desired by any hosts coupled to the communication link. If, while waiting for a positive response to the queries issued, a request to join an additional multicast group is received, bandwidth availability on the communication link is examined to determine if adequate bandwidth is available for supporting the newly requested group addition. If adequate bandwidth is available, the newly requested group is added to those groups supported on the communication link.

Abstract: A request method for performing optical power management to accomplish planned addition and removal of wavelengths in an optical communications system is disclosed, wherein each wavelength has a path of transmission through the system. The method comprises communicating a request for a power ramp to at least one path network component in the path, determining that the path network component has made preparations for the power ramp, and performing a power ramp in response to the determination. Further, a response method for performing power management to accomplish planned addition and removal of wavelengths in an optical communications system is disclosed, wherein each wavelength has a path of transmission through the system. The method comprises receiving a request for a power ramp, making preparations for the power ramp, determining that the power ramp has been completed, and resuming normal operation in response to the determination.

Abstract: A coordinated method is provided for controlling dynamic gain equalization in an optical transport network. The method includes: detecting a deviation in optical power of an optical signal traversing the optical transport network along a transmission path, adjusting spectral profile of the optical signal at a first network element in the optical transport network, where the first network element is located in the transmission path downstream from the origination point of the deviation; and adjusting spectral profile of the optical signal at a second network element subsequent to the adjustment at the first network element, where the second network element is located in the transmission path downstream from the origination point and the first network element.

Abstract: A method for optimizing an established call routed across a network from an originating exchange to a destination exchange over a first connection path. The first connection path features a path metric of interest, such as administrative weight. A second connection path is identified which features an improved path metric, the path is made operative and the call is directed over the second connection path. Thereafter, the first connection path may be dismantled. The second connection path is preferably identified by signalling a call set-up message over the network, wherein the message incorporates a reporting field and each transiting exchange propagating the message updates the reporting field until it specifies the path metric of the replacement connection path traversed by the call set-up message. A connect message incorporating the reporting field back is signalled back to the originating exchange from the destination exchange.

Abstract: There is provided a method and apparatus for establishing a connection across a connection oriented network to enable communication between an originating network element and a destination network node. The originating network element is connected to source network node in the connection oriented network by a source communications channel which is addressable in the connection oriented network. The connection oriented network has a signalling infrastructure employing a network signalling protocol for establishing connections within the connection oriented network. A connection establishment request message is generated for requesting the establishment of the connection between the originating network element and the destination network node and includes information identifying the source and destination communications channels. A proxy connection establishment request message is sent from a network controlling element to the connection oriented network over a proxy signalling link provided therebetween.

Abstract: A method of converting a permanent connection, such as a PVC, into a signalled permanent connection, such as an S-PVC, in a connection-orientated network, such as an ATM network, without service disruptions. The method includes the steps of: (a) establishing signalling links between each network node along the path of the permanent connection; (b) providing information to identify the cross-connections along the path; (c) incorporating the cross-connect identification information in a call set-up message; (d) signalling the call set-up message along the path from a source network node to a destination network node; and (e) associating the cross-connection of each node along the path with the appropriate signalling links in order to form the signalled permanent connection. The cross-connect identification information may be a unique call identifier for the permanent connection, in circumstances where the call identifier is associated with the permanent connection cross-connections prior to Step (d).

Abstract: A method of re-establishing a communications connection in a network element, a network element and a switched connection communications network are provided. The communications connection is re-established after a failure occurs affecting the communications connection. The network element is a network element in a switched connection communications network over which the communications connection is provisioned in a source-to-destination bearer path. The bearer path includes a cross-connection in the first-mentioned network element. The cross-connection is associated with the communications connection prior to the failure at a time when the communications connection is provisioned.

Abstract: The method of potentially recovering from a short term signalling failure in a switched connection data transmission network comprises the steps of: (a) establishing a unique, network-wide, identifier for each call; (b) incorporating the unique identifier in a call setup message transmitted to each network element in the path of the call; (c) linking the unique call identifier with each bearer channel cross-connect associated with the call; and (d) upon detection of a failure in a signalling network which affects the call, (i) actuating a timed release of the cross-connects, (ii) re-transmitting the call setup message, including the unique call identifier, to each network element involved in placing the call, (iii) re-linking the unique call identifier with the surviving cross-connects thereby reclaiming the cross-connects, and (iv) aborting the release of the cross-connects provided they have all been timely reclaimed.

Abstract: The method of potentially recovering from a short term signalling failure in a switched connection data transmission network comprises the steps of: (a) establishing a unique, network-wide, identifier for each call; (b) incorporating the unique identifier in a call setup message transmitted to each network element in the path of the call; (c) linking the unique call identifier with each bearer channel cross-connect associated with the call; and (d) upon detection of a failure in a signalling network which affects the call, (i) actuating a timed release of the cross-connects, (ii) re-transmitting the call setup message, including the unique call identifier, to each network element involved in placing the call, (iii) re-linking the unique call identifier with the surviving cross-connects thereby reclaiming the cross-connects, and (iv) aborting the release of the cross-connects provided they have all been timely reclaimed.

Abstract: A method is disclosed for detecting and diagnosing faults in a network. The network has a plurality of nodes through which switched virtual connections can be established. First, all attempts at establishing routes through the network are recorded. Then, the location of a failure is determined by analyzing the attempted routes.

Abstract: A method is disclosed for detecting and diagnosing faults in a network. The network has a plurality of nodes through which switched virtual connections can be established. First, all attempts at establishing routes through the network are recorded. Then, the location of a failure is determined by analyzing the attempted routes.