Link discovery and verification using loss of light

Abstract

Systems and methods for link discovery and verification that minimize the need for line termination resources to generate and interpret packets. According to one aspect of the present invention, a method for operating a first node in a data communication network to verify connectivity to a second node includes sending a request for verification of connectivity to the second node that identifies an IP address of the first node, a port of the first node, and an IP address of the second node. The method also includes toggling a signal emitted by the port, and notifying the second node of a toggling mode of the port. Finally, the method includes receiving a first message from the second node indicating whether the second node detected the toggling. The request for verification of connectivity is sent on a control channel via a control message separate from the signal and the first message.

Description

CROSS REFERENCE TO RELATED APPLICATION [0001] This U.S. Patent Application is a continuation of co-pending U.S. patent application Ser. No. 09 / 968,096, filed Sep. 28, 2001, which is incorporated herein by reference in its entirety.BACKGROUND OF THE INVENTION [0002] The present invention relates to data communication networks, and more particularly to systems and methods for discovering and verifying links between nodes. [0003] Internet traffic is typically forwarded from a source to a destination through a series of nodes connected by links. The nodes represent network devices such as routers, switches, etc. The links are physical media such as optical fiber, twisted pair, etc. and often connect a pair of nodes. Various protocols that control the forwarding of packets through a network depend on each node having a correct understanding of the links available to its immediate neighbors. [0004] Typically, discovery and / or verification of a link between two nodes is accomplished by an ...

AI Technical Summary

Benefits of technology

This approach significantly reduces the need for line termination resources, enabling rapid and cost-effective link verification in optical networks, especially beneficial for devices with many ports, by minimizing message exchanges and processing time.

Problems solved by technology

As will now be explained, however, this exchange of packets is problematic for an important new class of network devices.

The need to convert optical signals to electrical form and then perform switching and / or routing computations on the electrical signals has become a bottleneck for optical networks.

Since the optical signals pass through untouched, OXCs do not incorporate expensive hardware either for conversion to electrical form and reconversion to optical form, or for processing packets in accordance with a protocol.

This results in enormous savings in cost and extremely high throughput.

Thus, each LTU that is needed consumes a port and also a significant percentage of the available switching resources.

It becomes clear then that current link discovery and verification techniques are expensive to apply to optical switching equipment that is not otherwise capable of originating and / or interpreting packets via optical links.

However, DWDM equipment does not typically include the capability to terminate packets that are being carried by optical signals.

As with OXCs, this represents an obstacle to current link discovery and verification techniques.

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