In a telecommunication network, each node is provided with the same physical topology information relating to a physical construction of telecommunication paths included in the telecommunication network and with the same logical topology information relating to routing of telecommunication paths. When a failure occurs, restoration is effected by transmitting information relating to the failure that has occurred in the telecommunication network, throughout the network. Each node that receives the information relating to the failure determines alternative paths for bypassing the failure using the information relating to the failure, the physical topology information, and the logical topology information. Then service is switched to the alternative paths.
The specification describes a system and related method for determining the orientation of acoustic vector sensors installed in well bores that utilizes acoustic signals of known orientation in the casing to determine the orientation of the acoustic vector sensors. The acoustic vector sensors may be part of a string of acoustic sensors for acoustic or seismic surveys of subsurface formations, or may also be coupled to downhole devices for which orientations need to be know.
A primary station equipment unit transmits, to a secondary station equipment unit, a message transmission enable signal granting transmission of a PST message from the secondary station equipment unit, when a predetermined period of time defined for transmission elapses after the primary station equipment unit transmitted a downstream PST message in a redundancy switching process corresponding to the secondary station equipment unit.
There is described a cross-connect apparatus which can apply a cross-connect operation in place of a function of a hard switch that has conventionally been used for a purpose other than a cross-connect operation, by selection of line setting information used for path switching and service selection operations, and by performing a cross-connect operation based on the information, thereby preventing redundant configuration of the cross-connect apparatus and diminishing power consumption.
A link based network protection path calculation mechanism wherein a protection route is calculated that is guaranteed not to traverse the link it is intended to protect. The mechanism takes advantage of the fact that the same color cannot pass twice through the same optical fiber. The protection path is determined by eliminating all colors from the logical topology of the network except for the color corresponding to the link to be protected before executing the search algorithm. This serves to guarantee that the protection path calculated will not traverse the same physical fiber as the link to be protected. Virtual colors can be assigned to the links running through fiber bundles such that they do not pass through the same fiber/bundle twice.
The present invention provides layer one, two and three (L1/L2/L3) Integration and L1 cut-through path utilization in an apparatus and method of fault recovery. A switch combines an IP router with L2 capabilities, and an L1 cross connect (optical or electrical). A network of such switches is configured with label switched paths (LSP) that correspond to layer 1 (L1) cut-through paths. The layer 2 (L2) cut-through path is over laid on the L1 cut-through path and the L2 cut-through path is used for IP data flows. Preferably, the L2 cut-through paths are defined as label switched paths (LSP) and the L1 cut-through paths are each an end-to-end path established with L1 cross connects associated with each switch.
