Abstract: In one embodiment, first optical signal can be generated at a first end of an optical fiber segment at a first time. The first optical signal can be detected at a second end of the optical fiber segment at a second time. A second optical signal can be generated at a second end of the optical fiber segment at a third time in response to the detection of the first optical signal. The second optical signal can be detected at the first end of the optical fiber segment at a fourth time. A length of the optical fiber segment can be determined based on a difference between the second time and the first time, a difference between the third time and the second time, and a difference between the fourth time and the third time.

Abstract: In one embodiment, an apparatus can include: (i) logic configured to detect an advanced warning indication, such as for a degraded signal condition, on a first link between first and second network devices, where the detection can utilize a number of corrected bits and forward error correction (FEC), for example; and (ii) logic configured to reroute packet traffic from the first link to a second link when the degraded signal condition is detected.

Abstract: A system for transmitting data to a first circuit that transmits and receives data at a first rate from a second circuit that transmits data at second rate that is greater than the first rate. This invention includes an interface that transmits pause frames to the second circuit in response to an event in order to halt transmission from the second circuit to the first circuit. The second circuit then halts transmitting data until a message to resume transmission is received.

Abstract: Methods and apparatus for efficiently utilizing an optical control plane distinct from an electronic control plane to facilitate the setup of paths in a dense wave division multiplexing network are disclosed. According to one aspect of the present invention, a method includes receiving a probe arranged determine the optical feasibility of a first path, and determining a probability of success associated with the probe. The probability of success indicates a likelihood that the probe will be successfully routed on the first path to the destination, and is associated with a particular wavelength. A second path on which to route the probe is dynamically identified if the probability indicates a low likelihood of successful routing on the first path. Finally, the method includes determining if a notification associated with the probe has been received, and altering the probability of success based on the notification if the notification has been received.

Abstract: In one embodiment, first optical signal can be generated at a first end of an optical fiber segment at a first time. The first optical signal can be detected at a second end of the optical fiber segment at a second time. A second optical signal can be generated at a second end of the optical fiber segment at a third time in response to the detection of the first optical signal. The second optical signal can be detected at the first end of the optical fiber segment at a fourth time. A length of the optical fiber segment can be determined based on a difference between the second time and the first time, a difference between the third time and the second time, and a difference between the fourth time and the third time.

Abstract: In one embodiment, an apparatus can include: (i) logic configured to detect an advanced warning indication, such as for a degraded signal condition, on a first link between first and second network devices, where the detection can utilize a number of corrected bits and forward error correction (FEC), for example; and (ii) logic configured to reroute packet traffic from the first link to a second link when the degraded signal condition is detected.