Cisco Technology, Inc.

Robert A Hall

Andrew J Thurston

Douglas E Duschatko

Lane Bryon Quibodeaux

Lane Byron Quibodeaux

Vahid Parsi

Stephen Patrick Kolecki

A method, apparatus and system are disclosed that more efficiently maps data into standard SONET concatenated payloads for transmission over established SONET networks. Framing information is added to a data stream to identify the beginning and ending locations of a payload. Next, the framed data stream is formatted into a non-standard STS-Nc packet. Two or more non-standard STS-Nc packets are combined to form a pseudo-standard STS-Nc packet that is supported by the established SONET network. According to one embodiment, a one Gbps Ethernet packet is framed using HDLC formatting, then formatted into an STS-24packet. Two STS-24packets are combined to form a pseudo-standard STS-48packet. In addition, the one Gbps Ethernet packet can be stored and retimed to the SONET data rate and transmitted across an established SONET network.

Non-standard concatenation mapping for payloads

In a data transmission network, such as SONET, a method and apparatus for the generation of a path Alarm Insertion Signal (AIS) at the output of each of a number of concatenated pointer processors in response to a failure at the input of any one of the pointer processors. Each of the pointer processors has an input, an output and a bidirectional terminal that is coupled to a common node. Each of the pointer processors includes circuitry coupled to the input, the output and the bidirectional terminal that causes a predetermined logic level to be asserted at the bidirectional terminal in response to the appearance of an error signal at its input and that causes an AIS to appear at its output in response to either an error signal at its input or the assertion of the predetermined logic level at its bidirectional terminal.

Path AIS insertion for concatenated payloads across multiple processors

A method for determining a status of a buffer for use in converting between a standard SONET and a non-standard SONET frame is presented. The method determines the buffer's almost empty or almost full status based on a length of a transport gap of the non-standard SONET frame, wherein the standard SONET frame is formatted as a STS-N, and the transport gap of the non-standard SONET frame has been rearranged to provide a longer non-data region at the beginning of the non-standard SONET frame. The method then uses the buffer's almost empty or almost full status to trigger positive or negative stuffing. The method is used for maintaining communications when using asymmetrical gapping structures.

Buffer status in an asymmetrical gap environment

A method of generating a parity value is disclosed. The method includes reading a word from a data stream, determining if the word should be included in a parity calculation, and including the word in the parity calculation, if the word should be included in the parity calculation, and ignoring the word otherwise.

Method and apparatus for detecting errors in a backplane frame

A method and a communication circuit for directing control of communication signals in a concatenated payload in a communication circuit is disclosed. The method and apparatus includes receiving a multiplex order of the concatenated payload in M communication signals, dividing the M communication signals by three to determine a number Y, and determining the control of the M communication signals by designating the first signal of the M communication signals as a control signal, designating the second signal through a Yth signal of the M communication signals as being controlled by the immediately preceding signal thereto, and designating each Y+1th signal of the M signals through the Mth communication signal as being controlled by a signal Y positions prior thereto. The method and communication circuit includes communication signals that are synchronous transport signals. In an embodiment, the first signal of the M communication signals is a control signal read and write capability for frequency difference buffering using increment/decrement technology.

Fixed algorithm for concatenation wiring

An apparatus and method for a synchronous optical network (SONET) includes ordering a plurality of signals of a first type in one or more line cards for transmit to one or more types of line cards, wherein the ordering of the first type of signals creates a plurality of independent signals of a second type, and transmitting the plurality of the first type of signals to the one or more types of line cards, wherein the independence of the signals of the second type permits the one or more types of signals of the second type to be in an arbitrary order. The method and apparatus includes ordering in a plurality of modules to assign to a variable A a number of basic modules on the one or more line cards, assign to a variable B a number of processors adapted for STS-N signals on the one or more line cards, calculate a variable C by dividing A by B, C being the number of basic module channels common to each of the processors, calculate a variable D by dividing C by three, D being a number of contiguous channels, divide each STS-N signal into N/D portions, each portion including up to D bytes, and for each portion of the STS-N signal, select one of the number of processors adapted for STS-N signals, and transmit the portion of the STS-N signal to the one of the number of processors.

Channel ordering for communication signals split for matrix switching

An apparatus and method for detecting concatenation of payload data for an communication circuit is disclosed, wherein the payload data is dispersed over a first integrated circuit and one or more subsequent integrated circuits. The method and apparatus include determining whether each of the one or more subsequent integrated circuits have all channels therein designated as concatenation slaves, and communicating the determination to the first integrated circuit, the determination indicating that the one or more subsequent integrated circuits. According to an embodiment, the method and apparatus further include coupling the first integrated circuits to the one or more subsequent integrated circuits. The apparatus and method further include detecting concatenation on a first integrated circuit of the one or more integrated circuits, assigning one or more bi-directional ports coupled to the first integrated circuit as an input port, assigning each bi-directional port coupled to the one or more subsequent integrated circuits as output ports, and if any one integrated circuit among the subsequent integrated circuits includes a channel therein designated as a slave channel, providing an active high signal to the output port, the active high signal coupled to the input port of the first integrated circuit.

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Richardson, TX, United States of America

Robert A Hall