Abstract: Transport network interfaces operate to transport for Optical Transport Unit frames over an Optical Transport Network. Besides FEC bits for the Optical Transport Unit frames, the transmitting transport network interface provides sequences of error-determining bits for the Optical Transport Unit frames sent on working and protection communications channels. There is at least one sequence for each Optical Transport Unit frame, the number of bits in the at least one sequence much smaller than the number of bits in the Optical Transport Unit frame. The receiving transport network interface determines the bit error rates for the working and protection channels from the sequences of error-determining bits without decoding said Forward Error Correction bits and can select the working and protection channels accordingly.

Abstract: An apparatus comprising encryption logic that provides security for fiber-based communications may be implemented in accordance with an embodiment of the present invention. A data super frame is created by the encryption logic to comprise two or more data frames. Each of the data frames contains a payload portion. The encryption logic may receive one or more data payloads that are associated with a client signal. Using a single set of security control parameters, the encryption logic encrypts and stores a different encrypted payload in a payload portion of a different frame of the data frames in the data super frame. Instead of storing the set of security control parameters in a single data frame, the encryption logic stores the set of security control parameters in different sets of unused bytes associated with at least two different frames of the data frames.

Abstract: Methods and apparatus for efficiently allowing protection switch information to be communicated on bidirectional lines are disclosed. According to one aspect of the present invention, a method for communicating protection switch information from a first network element to a second network element across bidirectional links that include at least one working line and a protection line involves obtaining a generic framing protocol GFP frame at the first network element. The GFP frame has a payload area with a client payload field. The method also includes defining a command field associated with the GFP frame that is in the payload area but not in the client payload field, and storing protection switch information in the command field.

Abstract: Methods and apparatus for increasing the operational distance of multimode fibers are disclosed. According to one aspect of the present invention, an optical transmitter includes a framer that frames data and a scrambler that scrambles the data after the data is framed. The optical transmitter also includes an encoder that applies a forward error correction algorithm to encode the data after the data is scrambled, as well as a source that transmits the data across the multimode fiber after the data is encoded.

Abstract: Methods and apparatus for allowing containers in an optical transport network to be shared between users are disclosed. According to one aspect of the present invention, a first network element that is a part of an optical transport network includes a frame generator and an output arrangement. The frame generator creates a frame with a fixed stuff area that includes a first set of bits that provide channel identification information, a second set of bits that provide justification information, and a third set of bits that indicate either or both payload type information and client signal fail information. The output arrangement places the frame within a container for transport through the optical transport network. The bandwidth of the container is arranged to be utilized by a plurality of network elements including the first network element.

Abstract: A method and system for encapsulating a frame for transport over an optical transport network are disclosed. A method includes receiving a packet at a network device and encapsulating the packet. The packet is received from a network having a line frequency different than a payload frequency of the optical transport network and the encapsulated packet is configured for transport directly over the optical transport network without modification to compensate for the different frequencies.

Abstract: Methods and apparatus for providing tandem connection monitoring and performance monitoring capabilities in Ethernet and converged data link protocols are disclosed. According to one aspect of the present invention, a method for processing a packet which includes a preamble arrangement having at least one associated frame involves receiving a packet from a first network element included in a network path at a second network element included in the network path, and determining whether at least one error has arisen between a source of the network path and the second network element. When it is determined that an error has arisen between the source of the network path and the second network element, a first error count indication is inserted in the preamble arrangement to substantially account for the error.

Abstract: A transport interface for time division frames, in particular SDH frames transmitted between telecommunications network nodes according to a specified transport protocol, said nodes comprising first circuit means (SM) for processing said time division frames (TRM, TRM2) according to said specified transport protocol, and second circuit means (FP) apt to exchange second information streams (FDS) with said first circuit means (SM) through said transport interface (STI). According to the invention, said second information streams (FDS), exchanged by the transport interface (STI) with the first circuit means (SM) and with the second circuit means (FP), are simplified with respect to said time division frames (TRM1, TRM2) received from said node, in particular are composed by a data stream (BD, T_BD, R_BD) sent in a co-directional way and by an address information (EAR, T_EAR, R_EAR) sent by the transport interface (STI).

Abstract: Methods and apparatus for providing tandem connection monitoring and performance monitoring capabilities in Ethernet and converged data link protocols are disclosed. According to one aspect of the present invention, a method for processing a packet which includes a preamble arrangement having at least one associated frame involves receiving a packet from a first network element included in a network path at a second network element included in the network path, and determining whether at least one error has arisen between a source of the network path and the second network element. When it is determined that an error has arisen between the source of the network path and the second network element, a first error count indication is inserted in the preamble arrangement to substantially account for the error.

Abstract: A transport interface for time division frames, in particular SDH frames transmitted between telecommunications network nodes according to a specified transport protocol, said nodes comprising first circuit means (SM) for processing said time division frames (TRM, TRM2) according to said specified transport protocol, and second circuit means (FP) apt to exchange second information streams (FDS) with said first circuit means (SM) through said transport interface (STI). According to the invention, said second information streams (FDS), exchanged by the transport interface (STI) with the first circuit means (SM) and with the second circuit means (FP), are simplified with respect to said time division frames (TRM1, TRM2) received from said node, in particular are composed by a data stream (BD, T_BD, R_BD) sent in a co-directional way and by an address information (EAR, T_EAR, R_EAR) sent by the transport interface (STI).