Abstract: The disclosure generally relates to mechanisms to protect hybrid networking equipment at a port level granularity and thereby provide capabilities to specify the protection of client services on a port-by-port basis. For example, in one embodiment, a Virtual Connection Point (VCP) may be established as a termination point for a transport-side network connection and configured as a Layer 1 bridge/select connection to switch among any one of a plurality of backplane Layer 1 termination points. The plurality of backplane Layer 1 termination points may be protected using a link aggregation group, wherein a Layer 2 switch may be established to direct packets between the link aggregation group and the VCP configured as the Layer 1 bridge/select connection.

Abstract: Methods and systems can suppress invalid defect detection when Out-Of-Frame (OOF) conditions occur within an Optical Transport Network. One method for processing a report of a defect during an OOF condition may include detecting the OOF condition at a downstream node, detecting an indication of the defect caused by the OOF condition, suppressing a report associated with the indication of the defect, determining whether the OOF condition is clear, determining whether the indication of the defect is still present if the OOF condition is clear; and cancelling the report if the indication of the defect is not present. A network node which processes a report of a defect during an OOF condition may include a network interface, and a processor which is coupled to the network interface. The processor may be configured to perform a method for suppressing invalid defect detection during OOF conditions.

Abstract: A method and system for determining timers in a High Level Data Link Control (HDLC) Traffic Manager (HTM) state machine are disclosed. According to one aspect, the invention provides for determining a transit delay between two nodes by sending a first packet having a delay measurement byte to a second node that is on a link between the first node and the second node. A measured delay value is determined based on the delay between a time of sending the first packet to the second node and receiving a second packet from the second node. The timer values of the HTM state machine are set based on the measured delay value.

Abstract: Embodiments of the present invention provide a method and system for reserving a connection's home path resources and restoring the connection on a link that includes a reserved priority bandwidth. A bandwidth advertisement indicating that the reserved priority bandwidth is available is analyzed and a restoration request requesting to route the connection on the link is sent. The reserved priority bandwidth is used to route the connection when the connection has a reserved home path on the link. When the connection has a reserved home path not on the link, a determination is made as to whether a normal priority bandwidth on the link is available and whether the connection is unrestorable on another link. The reserved priority bandwidth is used to temporarily route the connection when normal priority bandwidth on the link is unavailable and the connection is unrestorable on another link.

Abstract: The present disclosure provides Optical Transport Network (OTN) port protection systems and methods using flexible switch criteria. Specifically, the OTN port protection systems and methods provide linear protection in OTN such as 1+1 Protection with Automatic Protection Switching (APS) and/or 1+1 Subnetwork Connection Protection (SNCP) Protection. The OTN Port Protection with flexible switch criteria allows a user to provision a protection application on an OTN Port and select a switch criteria, Section Monitoring, Path Monitoring, or Tandem Connection Monitoring, without considering the provisioning state of an Optical channel Data Unit level k (ODUk) entity. The ODUk entity may either be cross-connected in the LO case or terminated in the HO case. The ODUk entity may be provisioned independently, after the port protection has been established.

Abstract: The present disclosure provides improvements with respect to in-band control plane signaling, virtualized channels, and tandem connection monitoring in optical networks utilizing Synchronous Optical Network (SONET), Synchronous Digital Hierarchy (SDH), Optical Transport Network (OTN), and the like. In an exemplary embodiment, the present disclosure includes an optical network operating a control plane with in-band signaling utilizing SONET/SDH path level overhead. In another exemplary embodiment, the present disclosure includes an optical network operating virtualized SONET/SDH or OTN channels with manually cross-connections at intermediate line terminating elements. In yet another exemplary embodiment, the present disclosure includes a tandem connection monitoring selection method across multiple operator domains.

Abstract: The present disclosure provides systems and methods for inserting pseudo-noise in a data stream based on an unacceptable input data sequence in an optical network thereby preventing unnecessary loss of frame in SONET/SDH or Optical Transport Network (OTN) systems. The present disclosure includes a SONET/SDH or OTN framer, a transceiver, and a method for detecting an unacceptable data sequence or pattern and inserting a keep-alive or pseudo-noise sequence in the data sequence to maintaining framing on subsequent network elements, framers, transceivers, etc. For example, the present invention, upon receiving an unacceptable pattern of zeros or low ones density caused by a loss of signal condition or the like, may insert a pseudorandom noise pattern into the transmitted frame. This allows the downstream network element to continue a frame lock on the incoming signal, and thus keep the frame overhead and data communications channels from being lost.

Abstract: The present disclosure provides Network Element (NE) clock synchronization using Optical Transport Network (OTN) delay measurement systems and methods such as described in ITU-T G.709 (12/2009) “Interfaces for the Optical Transport Network (OTN)” and G.798 (10/2010) “Characteristics of optical transport network hierarchy equipment functional blocks”. OTN provides a Delay Measurement (DM) function to measure fiber path latency between two network elements to within microsecond accuracy. The convergence of packet switching and OTN transport into the same network element allows the sharing of this information between the two applications. The OTN delay measurement value can be used to synchronize two network element clocks to within microsecond accuracy without the need for a costly GPS synchronization solution or reduced accuracy NTP solutions.

Abstract: The present disclosure provides improvements with respect to in-band control plane signaling, virtualized channels, and tandem connection monitoring in optical networks utilizing Synchronous Optical Network (SONET), Synchronous Digital Hierarchy (SDH), Optical Transport Network (OTN), and the like. In an exemplary embodiment, the present disclosure includes an optical network operating a control plane with in-band signaling utilizing SONET/SDH path level overhead. In another exemplary embodiment, the present disclosure includes an optical network operating virtualized SONET/SDH or OTN channels with manually cross-connections at intermediate line terminating elements. In yet another exemplary embodiment, the present disclosure includes a tandem connection monitoring selection method across multiple operator domains.

Abstract: A method and system for determining timers in an High Level Data Link Control (HDLC) Traffic Manager (HTM) state machine are disclosed. According to one aspect, the invention provides for determining a transit delay between two nodes by sending a first packet having a delay measurement byte to a second node that is on a link between the first node and the second node. The method also includes receiving a second packet with the delay measurement byte from the second node. The delay measurement byte sent by the second node is adjusted by the second node to indicate its receipt by the second node. A measured delay value is determined. The measured delay value is the delay between a time of sending the first packet to the second node and receiving the second packet from the second node. The measured delay value is determined by the hardware of the first node. Upon determining the measured delay value, timer values of the HTM state machine are set based on the measured delay value.

Abstract: The present disclosure provides systems and methods for inserting pseudo-noise in a data stream based on an unacceptable input data sequence in an optical network thereby preventing unnecessary loss of frame in SONET/SDH or Optical Transport Network (OTN) systems. The present disclosure includes a SONET/SDH or OTN framer, a transceiver, and a method for detecting an unacceptable data sequence or pattern and inserting a keep-alive or pseudo-noise sequence in the data sequence to maintaining framing on subsequent network elements, framers, transceivers, etc. For example, the present invention, upon receiving an unacceptable pattern of zeros or low ones density caused by a loss of signal condition or the like, may insert a pseudorandom noise pattern into the transmitted frame. This allows the downstream network element to continue a frame lock on the incoming signal, and thus keep the frame overhead and data communications channels from being lost.