Abstract: A network arrangement where traffic elements of network nodes are programmable. A traffic element comprises electrically controllable transceiver pool having one or more ports that are coupled to an electrically controllable optical director that has all-optical information communication paths. The transceiver pool has one or more customer connection points in addition to the one or more connection points that connect to the optical director, and is adapted to couple a signal from any of the customer connection points to the optical director, at a particular wavelength. The choices for the specific coupling within the optical director and of the wavelengths are specified by control signals that are applied to the transceiver pool and to the optical director.

Abstract: A method for structuring SONET rings in a network is disclosed, along with a method for redirecting traffic among SONET rings when a fault causing traffic outage on a single SONET ring is detected. First, SONET rings are structured into “families” sharing common offices, with each family containing an additional “protection ring”. When a service-affecting alarm is detected in a SONET ring, it is determined whether there are any service alarms on a protection ring in the SONET ring family. It is also determined whether or not the protection ring is already in use. If the protection ring is not in use and no alarms are detected in the protection ring, the protection ring is marked as being in use. Traffic from the ring in which the service alarm is detected is then re-routed onto the protection ring. A method is also given for directing traffic back to the original SONET ring after the failure is repaired.

Abstract: An in-band fault detection and isolation system and method for networks such as Synchronous Optical Network/Synchronous Digital Hierarchy (SONET/SDH) networks. Fault detection may be quickly and efficiently performed by a network without requiring modification to any add/drop multiplexers (ADMs) and/or without the involvement of an external network management system (NMS). To accomplish this without violating SONET/SDH standards, a new signal, called a fault isolation signal in the path (FIS-P), is proposed. The FIS-P may be used in lieu of an AIS-P to support special applications on certain digital cross connect (DCS)-to-DCS path segments. Moreover, the present invention may be implemented such that the behavior, of path terminating equipment (PTE) is unaffected.

Abstract: An alarm and restoration system (28) accomplishes restoration in a ring network (10l) by monitoring network traffic to detect the occurrence of a single failure arising from a failed optical service path (14i) and the occurrence of a double failure arising from a failed optical service path and an occupied optical protection path (16i). In case of a single failure, the alarm and restoration system (28) restores traffic in the network itself by routing traffic on a restoration path. In the even of a double failure, the alarm and restoration system (28) routes traffic from the failed ring network through an Optical Cross-Connect mesh (22) to transform the double failure into a single failure that can be restored in the network itself.