At+t Corp.

At&t Bell Laboratories

American Telephone and Telegraph, Co.

Martin Eisenberg

Moshe Segal

Jack M Holtzman

Nader Mehravari

An embodiment of the system and method of the present invention organizes the recovery of a communications network to minimize the interference between the recovering nodes and thus allows for a faster recovery. A metered rate is calculated at which nodes recover from a major network failure; when nodes recover at the metered rate, the network recovers quickly but without performance degrading interference. A measure of the interference between recovering nodes may be created; the interference measure may be used to partition the network, where the nodes within each partition set interfere minimally with each other during recovery and each set recovers separately. Recovering items (nodes or sets) may be sequenced so that each item recovers substantially separately in time, but where adjacent sequence items recover with some temporal overlap. Alternate embodiments may organize any system of items such as objects or devices competing for resources to minimize interference; a metered rate or measure of interference may be created, and the items may be partitioned and sequenced.

Network disaster recovery and analysis tool

In an optical switching network, a master optical space switch is interconnected with remote slave equipment for switching block-multiplexed messages among the remote equipment. The master optical space switch responds to a frequency reference clock and steps through a sequence of states, or configurations, for establishing various routes among the remote equipment for appropriately routing the messages to correct destinations. The frequency reference clock also is distributed to the remote equipment. During one of the states per frame, each remote slave equipment transmits a distinct signature signal. All of the slave equipments are connected through the master optical space switch to return to themselves their own signals transmitted during that time slot. Each remote slave equipment compares the returned signal with the originally transmitted signature signal to determine how much the round trip delay has varied from a nominal value. Phase of a local control clock signal in the slave equipment is adjusted to counteract the variation of the round trip delay. Thus the operation of the slave equipment is adjusted into synchronization with the master optical space switch so that messages transmitted from the slave equipment arrive at the master optical space switch at the appropriate time with respect to the periodic reconfigurations of the master optical space switch.

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Holmdel, NJ, United States of America

Martin Eisenberg