Aspects of methods and systems for frequency multiplexing suitable for Data Over Cable Service Interface Specification (DOCSIS) are provided. A system for multiplexing signals according to frequency comprises a DOCSIS port interface, an upstream interface, a downstream interface, and a circulator subsystem. The DOCSIS port interface comprises a plurality of channel filters. The upstream interface is operably coupled to a first channel filter of the plurality of channel filters, and the downstream interface is operably coupled to a second channel filter of the plurality of channel filters. The circulator subsystem is able to direct a first signal from the upstream interface to the DOCSIS port interface and is able to direct a second signal from the DOCSIS port interface to the downstream interface.

A circuit having multiple inputs and multiple outputs the circuit being for switching signals received at any of the inputs to any of the outputs, the circuit comprising: a first switch matrix, the first switch matrix being capable of directing signals received at the inputs of the circuit to multiple first intermediate ports; a second switch matrix, the second switch matrix being capable of directing signals received at multiple second intermediate ports to multiple third intermediate ports, the number of the second intermediate ports being less than the number of the inputs of the circuit; one or more primary bypass links, each primary bypass link being capable of coupling one or more of the first intermediate ports to a respective one or more of the outputs of the circuit independently of the second switch matrix; a first redirection layer, the first redirection layer being capable of, for each first intermediate port, directing a signal received at that first intermediate port to a primary bypass link or to a second intermediate port; and a second redirection layer, the second redirection layer being capable of directing signals received at each of the primary bypass links to a respective one or more outputs of the circuit, and directing signals received at each of the third intermediate ports to a respective one or more outputs of the circuit.

A cascadable AGC amplifier in a signal distribution system includes a low noise cascadable amplifier having a through path and a cascadable output. The cascadable amplifier is also configured to provide AGC over a predetermined input power range. The cascadable AGC amplifier can be configured to provide gain or attenuation. When the cascadable AGC amplifier is implemented in a signal distribution system, typically as part of a signal distribution device, an input signal can be gain controlled and supplied to multiple signal paths without distortion due to degradation of signal to noise ratio or distortion due to higher order amplifier products. The distributed signal is not significantly degraded by distortion regardless of the number of cascadable AGC amplifiers connected in series or the position of the cascadable AGC amplifier in the signal distribution system.

A Fibre Channel over Ethernet (FCoE) network can be inexpensively extended by additional switches (220x) that do not have a full FCoE functionality, e.g. do not have full E-port functionality. The additional switches may or may not have unique Domain IDs. A virtual switch fabric can be extended by such additional switches.

As compared to the conventional method, a non-blocking multicast switching system is provided in which the number of switches to be operated can be reduced and the path switching can be quick. A multicast switching system with an input stage, a middle stage, and an output stage, including a plurality of input switch elements of receiving/transmitting streams from input sources/to the middle stage, a plurality of middle switch elements of receiving/transmitting streams from the input switch elements/to the output stage, the plurality of middle switch elements being grouped into a plurality of groups and a plurality of output switch elements of receiving/outputting streams from the middle switch elements/to output destinations, wherein the input switch elements transmit the streams to each of the plurality of groups.

A network topology system comprises a plurality of nodes, each of the plurality of nodes having a set of connection rules which is built by the steps of: generating a series of prime number differences; generating a series of communication strategy numbers; extracting as many terms as the number of connecting nodes from a recursive sequences to serve as an index series; generating a series of connection strategy numbers by extracting the Nth terms from the series of communication strategy numbers, wherein N stands for each number of the index series; and generating a series of connecting nodes numbers by calculating the sum of each odd number and each term of the series of connection strategy numbers so as to build the connection rules for each odd-numbered node to connect the nodes numbered in corresponding with the numbers of the connecting nodes number series.

Techniques including controlling coupling and uncoupling of RF ports included in an RF switch matrix including first-side RF ports and second-side RF ports, where each of the first-side RF ports is configured to be selectively coupled to at least one of two or more of the second-side RF ports, identifying one or more of the second-side RF ports as active ports including an active port, causing the RF switch matrix to couple the active port to a signal port included in the first-side RF ports, obtaining at least one of a bit error rate and a signal to noise ratio for a demodulation of an RF stream received via the active port, and causing, in response to at least one of the bit error rate or the signal to noise ratio, the RF switch matrix to couple the signal port to a spare port included in the second-side RF ports.

Embodiments including methods, systems, and apparatuses for distributing, processing, and reacting to path information distributed via a service-agnostic packet fabric for the purpose of enabling path selection are disclosed. By configuring two ingress line cards to send path quality words to each other via the switch fabric, compare the path quality words, and determine whether to transmit traffic to an egress line card via the switch fabric based on the comparison of the path quality words, the embodiments enable a central switch fabric to be unaware of the paths that it carries, and enable both ingress and egress bandwidth of the switch fabric to be sized according to the facilities for which it is terminating. The switch fabric does not need to support working and protection paths simultaneously in some embodiments, allowing it to be scaled appropriately to termination facilities.

A Fibre Channel over Ethernet (FCoE) network can be inexpensively extended by additional switches (220x) that do not have a full FCoE functionality, e.g. do not have full E-port functionality. The additional switches may or may not have unique Domain IDs. A virtual switch fabric can be extended by such additional switches.

A Fibre Channel over Ethernet (FCoE) network can be inexpensively extended by additional switches (220x) that do not have a full FCoE functionality, e.g. do not have full E-port functionality. The additional switches may or may not have unique Domain IDs. A virtual switch fabric can be extended by such additional switches.