Abstract: Apparatus for monitoring a packet switched network, the apparatus comprising: at least one port for receiving and transmitting packets; a local clock; and a packet inspector that uses time from the local clock to timestamp packets received at a port of the at least one port, and additionally copies timing information from received timing distribution packets, which are transmitted from a master clock to a slave clock in order to discipline the slave clock, and forwards the received packets for transmission from a port of the at least one port; wherein the apparatus uses the timestamp of a received timing distribution packet and the copied timing information to monitor timing distribution performance of the network .

Abstract: A method and system in which a Digital Subscriber Line Access Multiplexer (DSLAM) that is part of a DSL (Digital Subscriber Line) system is able to provide synchronous services to end user equipment connected to the DSLAM via a DSL link and Customer Premises Equipment (CPE). A sniffer device having direct or indirect access to a Primary Reference Clock (PRC) of the DSL system calculates the phase difference between the PRC and the DSLAM's Local Timing Reference (LTR). The phase difference is sent to the CPEs requiring accurate reference clock frequency. The CPEs are able to derive the PRC from the phase difference information transmitted by the sniffer device thus enabling synchronous end user equipment operation.

Abstract: A frequency reference, comprising: an optical waveguide closed on itself so that a light pulse inserted into the waveguide circulates therein; a light source coupled to the waveguide and controllable to generate a light pulse that circulates in the waveguide; and a detector coupled to a region of the waveguide that generates an output pulse each time the circulating light pulse passes the region.

Abstract: A small form-factor transceiver module performs protocol translation, in addition to the conventional electrical and/or optical transmission media conversion. Such protocol conversion may enable transport of traffic from limited-range primary networks over long-range secondary networks, such as extension of Ethernet networks over low-rate TDM links. Additionally, such protocol conversion may enable interworking between different networks of differing technologies, such as transport of ATM traffic over Ethernet networks. The transceiver module may be a Small Form Factor transceiver (SFF), Small Form Factor pluggable module (SFP), Gigabit Interface Converter (GBIC) or any similar small form-factor module consisting of a housing, internal electronic circuitry and optionally optical components, and associated electrical or optical connectors.

Abstract: A system and method for extending the distance that xDSL services are able to be provided to subscribers. A DSLAM located at a Central Office is connected to a general-purpose network, such as the Internet. The DSLAM is additionally connected to a first fiber optic transceiver. The first fiber optic transceiver is connected via a fiber optic link to a second fiber optic transceiver located proximate to the subscribers' premises, preferably in a street cabinet. Each subscriber premise's equipment is connected to the broadband transceiver via subscriber lines. Electrical signals to be transmitted between the Central Office and the subscribers' premises are utilized to form a frequency division multiplexed signal. The frequency division multiplexed signal is used to modulate a light subcarrier for transmission across the fiber optic link.

Abstract: A method and system for processing one or more TDMs for communication over IP networks, such as the Internet, includes encapsulating ATM cells (packets) using AAL1 cells within UDP over IP frames to provide synchronous bit streams into fixed size cells. This allows for an IP header to be added to the packets, with such packets forwarded to its destination host across the IP network. The destination regenerates the clock, decrypts/strips the IP header and delivers a synchronous bit stream. Furthermore, an adaptive clock is provided for clock transfer across the network. The adaptive clock regenerates the far end T1/E1 receive clock out of the incoming arrival frame rate. Frames arriving from the IP network are stored in a buffer and taken out for TDM stream assembly.

Abstract: A telecommunications apparatus is disclosed for use in conjunction with a local switch. The apparatus operates in a bypass mode for messages that do not require compression/decompression, and in a pass-through mode for those which do. A selective compressor/decompressor is provided to decompress incoming information for which the local switch is to operate in pass through mode and to compress outgoing information for which the local switch has operated in pass through mode. A selective masker/demasker is operative to expand information to be bypassed by the switch without decompressing the information from a compressed form to an expanded form and to restore information bypassed by the switch from the expanded form to the compressed form.