Fujitsu Corporation

Fujitsu Network Communications, Inc.

Roy McNeil

Jae Park

David Delgadillo

Stephen Joseph Brolin

David Michael Colven

Bruce Pietsch

Jon Allingham

A system provides more cost and bandwidth efficient utilization of a SONET network having both a Working path and a Protection path by using both communication paths to carry data. A system for communicating data over a Synchronous Optical Network/Synchronous Digital Hierarchy, the system comprises an Optical Line Termination unit operable to interface with a plurality of Synchronous Optical Network/Synchronous Digital Hierarchy communication paths, and communicate different data on each of the plurality of Synchronous Optical Network/Synchronous Digital Hierarchy communication paths.

Utilizing the protecting bandwidth in a SONET network

A communications network employs an optical communications medium carrying a synchronous communications transport signal including a number of time-division-multiplexed (TDM) channels. A number of bridges include respective interfaces to associated local area network (LAN) segments, and the bridges are coupled to the communications medium by associated add-drop circuits. Each add-drop circuit groups the TDM channels of the transport signal into bundles, each bundle being associated with a different bridge. Each add-drop circuit transmits data traffic originated by the associated bridge on only the bundle associated with the bridge, receives data traffic from the other bridges via the bundles associated with the other bridges, forwards the received data traffic to the associated bridge, and re-transmits at least some of the received data traffic on the bundles for receipt by another of the add-drop circuits.

Full multicast connectivity over SONET

A communications network includes a communications medium with a synchronous communications transport signal including time-division-multiplexed (TDM) channels, bridges having respective interfaces to different local area network (LAN) segments, and add-drop circuits coupling associated ones of the bridges to the communications medium. Each add-drop circuit groups TDM channels of the communications transport signal into a bundle, and schedules the use of the bundle to carry data traffic originated by the associated bridge and to carry data traffic originated by the other bridges. Data traffic originated by the associated bridge and destined for the other bridges is transmitted on the bundle in accordance with the scheduling. For data traffic received from the other bridges via the bundle, it is determined whether the received data traffic is destined for the associated bridge, and if so then it is forwarded to the associated bridge. Receieved data traffic destined for the other bridges is re-transmitted on the bundle in accordance with the scheduling for receipt by the add-drop circuit associated with the destination bridge.

Shared VT connectivity over SONET

A network device transfers variable-length data frames across a synchronous network employing a multiple-channel synchronous transport signal. Encapsulation logic encapsulates each data frame in a point-to-point frame including a body portion of the data frame and a length value located in a beginning portion of the point-to-point frame. Segmentation logic divides each point-to-point frame into fixed-sized segments, a first segment carrying the beginning portion of the point-to-point frame. Transmitting circuitry transmits the frame segments as payloads of at least one channel of the synchronous transport signal, the payloads being marked so as to be identifiable. Receiving circuitry receives payloads of at least one channel of the synchronous transport signal and from each received set of payloads regenerates a corresponding point-to-point frame using the length value from the first segment thereof. De-capsulation logic de-capsulates each regenerated point-to-point frame to recover the corresponding data frame.

Transmission of data frames using low-overhead encapsulation and multiple virtual tributaries in a synchronous optical network

LAN interface logic ( ) receives frames from a LAN segment ( ), and frame transport logic ( ) transfers frames to and from an ATM network. Forwarding logic ( ) is used to (i) determine whether a mapping between a destination address (DA) and a virtual connection (VC) in the ATM network exists, (ii) forward frames containing a known DA to the frame transport logic for transfer to the ATM network, (iii) forward frames containing unknown DAs to the frame transport logic for transfer to a broadcast and unknown server (BUS ) in the ATM network, and (iv) pass unknown DAs to a LAN emulation client (LEC) processor ( , FIG. ) to resolve the address. The LEC processor creates a LAN emulation address resolution protocol (LE_ARP) request message containing the unknown DA, and the LE_ARP request message is transferred to a LAN emulation server (LES ). The LES returns an ATM address of a remote LEC via which the destination node can be reached. The LEC processor uses the ATM address to establish a new VC to the destination node, and provides the DA-VC mapping to the forwarding logic for use in forwarding subsequently received frames.

Growing community of inventors

Warwick, NY, United States of America

Roy McNeil