摘要:
Methods, systems, and apparatuses related to a communication switch are disclosed herein. In some embodiments, the communication switch may be configured to transmit TDM, ATM and/or packet data from an ingress service processor, through a plurality of switch elements, to an egress service processor. Other embodiments may be described and claimed.
摘要:
A network switch includes at least one port processor and at least one switch element. The port processor has an SONET OC-x interface (for TDM traffic), a UTOPIA interface (for ATM and packet traffic), and an interface to the switch element. In one embodiment, the port processor has a total I/O bandwidth equivalent to an OC-48, and the switch element has 12×12 ports for a total bandwidth of 30 Gbps. A typical switch includes multiple port processors and switch elements. A data frame of 9 rows by 1700 slots is used to transport ATM, TDM, and Packet data from a port processor through one or more switch elements to the same or another port processor. Each frame is transmitted in 125 microseconds; each row in 13.89 microseconds. Each slot includes a 4-bit tag plus a 4-byte payload. The slot bandwidth is 2.592 Mbps which is large enough to carry an E-1 signal with overhead. The 4-bit tag is a cross connect pointer which is setup when a TDM connection is provisioned. The last twenty slots of the frame are reserved for link overhead. Thus, the frame is capable of carrying the equivalent of 1,680 E-1 TDM signals. For ATM and packet data, a PDU (protocol data unit) of 16 slots is defined for a 64-byte payload. The PDUs are self-routed through the switch with a 28-bit routing tag which allows routing through seven switch stages using 4-bits per stage. Bandwidth is arbitrated among ATM and Packet connections while maintaining TDM timing.
摘要:
A network switch includes at least one port processor and at least one switch element. The port processor has an SONET OC-x interface (for TDM traffic), a UTOPIA interface (for ATM and packet traffic), and an interface to the switch element. In one embodiment, the port processor has a total I/O bandwidth equivalent to an OC-48, and the switch element has 12×12 ports for a total bandwidth of 30 Gbps. A typical switch includes multiple port processors and switch elements. A data frame of 9 rows by 1700 slots is used to transport ATM, TDM, and Packet data from a port processor through one or more switch elements to the same or another port processor. Each frame is transmitted in 125 microseconds; each row in 13.89 microseconds. Each slot includes a 4-bit tag plus a 4-byte payload. The slot bandwidth is 2.592 Mbps which is large enough to carry an E-1 signal with overhead. The 4-bit tag is a cross connect pointer which is setup when a TDM connection is provisioned. The last twenty slots of the frame are reserved for link overhead. Thus, the frame is capable of carrying the equivalent of 1,680 E-1 TDM signals. For ATM and packet data, a PDU (protocol data unit) of 16 slots is defined for a 64-byte payload. The PDUs are self-routed through the switch with a 28-bit routing tag which allows routing through seven switch stages using 4-bits per stage. Bandwidth is arbitrated among ATM and Packet connections while maintaining TDM timing.
摘要:
The apparatus includes a separate line side inlet queue for each GFR VC, a single network side outlet queue for all GFR VCs, a single network side inlet queue for all GFR VCs, a single line side outlet bulk processing queue with a post queue packet processor followed by separate line side outlet queues for each line, a network side outlet queue monitor, and a line side inlet queue controller. The network side outlet queue monitor is coupled to the line side inlet queue controller so that the network side outlet queue monitor can send messages to the line side inlet queue controller. According to one of the methods of the invention, the network side outlet queue monitor sends messages to the line side inlet queue controller directing the line side inlet queue controller to send data from the line side GFR queues based on the status of the network side outlet GFR queue. According to another method of the invention, the line to side inlet queue controller discards packets for a GFR VC if congestion is indicated. According to still another method of the invention, the post queue packet processor discards packets above the PCR if the size of the line side outlet bulk processing queue exceeds a threshold size and discards packets above the MCR if discarding packets above the PCR fails to sufficiently reduce the size of the line side outlet bulk processing queue.
摘要:
A multiport single sided switching element is described for providing space and time switching between the input ports thereof and the output ports thereof in response to digital command signals for frames of digitally encoded data in a plurality of channels which is phase (bit) asynchronously coupled to any port of the switching element, the command signals being in for example the same channels as is the data. Every port of the single sided switching element is adaptable as either an inlet or an outlet and thus may be configured in a switching network as a one-sided, as a two-sided, or multisided switching element and includes a time division multiplexed bus for providing a space path between the ports of the switching element and further includes transmit and receive logic at each port responsive to command signals for coupling data from the input of any port to the TDM bus and additional logic at each port selectively responsive to command signals for bit synchronously extracting the data from the TDM bus in any channel thereby providing time slot interchange prior to coupling of data from the switching element to other switching elements. In a preferred embodiment, a sixteen port switching element is described.
摘要:
Apparatus and methods for modifying the address field of a packet are disclosed. The apparatus preferably includes an HDLC controller which finds the start of the packet and generates a signal indicative of the same, a sequence controller which receives the signal from the HDLC controller and controls the apparatus in response thereto, an address decoder receives the address field bytes from the HDLC controller and decodes them to provide a DLCI code therefrom, a RAM which is programmed as a DLCI translation table with outgoing DLCI codes being located at addresses which equate to the incoming DLCI codes, an address encoder which receives the outgoing DLCI code from the RAM and generates therefrom outgoing address field bytes, and a FIFO for storing the outgoing address field bytes until output is possible. Bytes received by the HDLC controller during the modification of the packet header are stored by the HDLC controller until the outgoing address field bytes are received at the FIFO. The stored bytes are then also forwarded to the FIFO, and thereafter, incoming data can be forwarded directly to the FIFO. The provided apparatus for modifying the address field of a packet introduces a minimum of delay into the packet transfer and reduces the amount of data storage required to effect the address field modification.
摘要:
A modular, expandable, non-blocking system for cross-connecting high speed digital signals is provided. The system is capable of connecting DSn, CEPTn, and STSn signals as desired, with lower rate signals being included as components of the high-rate signals or terminating on low speed lines, as desired. The system accomplishes its goals by converting all incoming signals into a substantially SONET format, and by processing all the signals in that format. The signals are typically cross-connected in the substantially SONET format, although an expandable non-blocking wide band cross-connect module is provided which cross-connects any like signals. If the outgoing signal is to be in other than SONET format, the substantially SONET formatted signal is reconverted into its outgoing format. To create a complete system, various modules are utilized, including: add/drop multiplexer means for add/drop applications of DS-0, DS-1, CEPTn signals, etc.; a SONET bus interface; a virtual tributary cross-connect module which cross-connects virtual tributary payloads in space, time, and phase to generate new substantially SONET formatted signals; a wide band cross-connect module; a DS-3/SONET converter; and front end interfaces including a DS3 line interface, and various STSn interfaces. The modules may be mixed and matched as desired to accommodate a multitude of applications.
摘要:
A telecommunication switching system includes a number of control circuits each of which is common to a plurality of line circuits and is coupled through time division multiplex links with two processor controlled interface circuits which are further coupled to a switching network. Line scanning information is processed in the control circuits to reduce the work load of the processor controlled interface circuits. Said line scanning information is then transmitted in the TDM links to the processor controlled interface circuits. The transmission priority among the control circuits is determined by a priority arrangement established for the system. A channel assignment controls the allocation of channels of the TDM links leading to parts of the line circuits.
摘要:
Interference caused by the propagation of a transmit signal transmitted from a transmit antenna to a receive antenna is effectively cancelled by an improved signal cancellation system. The system includes an interference cancellation signal generator that generates a time-delayed and amplitude-reduced representation of said transmit signal. A summing stage is operably coupled to the interference cancellation signal generator and the receive antenna. The summing stage subtracts the time-delayed and amplitude-reduced representation of the transmit signal from a receive signal to substantially cancel the interference. The interference cancellation signal generator preferably includes a novel programmable optical delay line that introduces a variable amount of optical delay to an optical signal derived from said transmit signal in addition to a thyristor-based sigma delta modulator that converts samples of the transmit signal to into a digital signal in the optical domain.
摘要:
Interference caused by the propagation of a transmit signal transmitted from a transmit antenna to a receive antenna is effectively cancelled by an improved signal cancellation system. The system includes an interference cancellation signal generator that generates a time-delayed and amplitude-reduced representation of said transmit signal. A summing stage is operably coupled to the interference cancellation signal generator and the receive antenna. The summing stage subtracts the time-delayed and amplitude-reduced representation of the transmit signal from a receive signal to substantially cancel the interference. The interference cancellation signal generator preferably includes a novel programmable optical delay line that introduces a variable amount of optical delay to an optical signal derived from said transmit signal in addition to a thyristor-based sigma delta modulator that converts samples of the transmit signal to into a digital signal in the optical domain.