WO2000042739A1 - Systeme et procede de simulation d'une topologie de reseau en etoile - Google Patents

Systeme et procede de simulation d'une topologie de reseau en etoile Download PDF

Info

Publication number
WO2000042739A1
WO2000042739A1 PCT/US1999/027066 US9927066W WO0042739A1 WO 2000042739 A1 WO2000042739 A1 WO 2000042739A1 US 9927066 W US9927066 W US 9927066W WO 0042739 A1 WO0042739 A1 WO 0042739A1
Authority
WO
WIPO (PCT)
Prior art keywords
signal
node
destination
network
signal channels
Prior art date
Application number
PCT/US1999/027066
Other languages
English (en)
Inventor
Near Margalit
Original Assignee
New Access Communications
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by New Access Communications filed Critical New Access Communications
Priority to AU17263/00A priority Critical patent/AU1726300A/en
Publication of WO2000042739A1 publication Critical patent/WO2000042739A1/fr

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J14/00—Optical multiplex systems
    • H04J14/02—Wavelength-division multiplex systems
    • H04J14/0278—WDM optical network architectures
    • H04J14/0283—WDM ring architectures
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J14/00—Optical multiplex systems
    • H04J14/02—Wavelength-division multiplex systems
    • H04J14/0227—Operation, administration, maintenance or provisioning [OAMP] of WDM networks, e.g. media access, routing or wavelength allocation
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J14/00—Optical multiplex systems
    • H04J14/02—Wavelength-division multiplex systems
    • H04J14/0227—Operation, administration, maintenance or provisioning [OAMP] of WDM networks, e.g. media access, routing or wavelength allocation
    • H04J14/0241—Wavelength allocation for communications one-to-one, e.g. unicasting wavelengths
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L12/00—Data switching networks
    • H04L12/28—Data switching networks characterised by path configuration, e.g. LAN [Local Area Networks] or WAN [Wide Area Networks]
    • H04L12/42—Loop networks
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L12/00—Data switching networks
    • H04L12/28—Data switching networks characterised by path configuration, e.g. LAN [Local Area Networks] or WAN [Wide Area Networks]
    • H04L12/42—Loop networks
    • H04L12/423—Loop networks with centralised control, e.g. polling
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L12/00—Data switching networks
    • H04L12/28—Data switching networks characterised by path configuration, e.g. LAN [Local Area Networks] or WAN [Wide Area Networks]
    • H04L12/42—Loop networks
    • H04L12/437—Ring fault isolation or reconfiguration
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L12/00—Data switching networks
    • H04L12/28—Data switching networks characterised by path configuration, e.g. LAN [Local Area Networks] or WAN [Wide Area Networks]
    • H04L12/44—Star or tree networks
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J14/00—Optical multiplex systems
    • H04J14/02—Wavelength-division multiplex systems
    • H04J14/0287—Protection in WDM systems
    • H04J14/0293—Optical channel protection
    • H04J14/0294—Dedicated protection at the optical channel (1+1)

Definitions

  • This invention relates to a network communication systems, and more specifically to a system and method of simulating a star network topology.
  • a communications network consists of a number of stations that want to talk to each other, and some medium (such as a wire) over which they can talk.
  • Some medium such as a wire
  • the star configuration is good for fast communication, but uses a lot of wire.
  • the ring configuration uses less wire but can be limited in communication.
  • Examples of communications networks include telecommunications systems (that can communicate voice, video, facsimile, electronic mail, etc.), cable television systems, and local area networks or other computer networks.
  • the traffic associated with current communications systems, or networks has increased markedly especially with the increased use of the world wide web (WWW or Internet).
  • the communication infrastructure e.g., the transmission media such as optical fiber, cable, wire, etc.
  • the communications infrastructure has a physical configuration that is referred to as a topology.
  • a ring topology connects network nodes in a loop, or ring. Information is transmitted from node to node around the loop to reach the destination node.
  • a ring topology has the advantage of minimizing the amount of transmission medium (e.g., fiber) that must be used to connect the nodes as compared. However, the amount of information that can be transmitted (the bandwidth) is limited in a ring topology.
  • a star topology connects branch nodes to a central node in a spoke-like fashion. Information is transmitted from one branch node to another via the central node.
  • a star topology has the advantage of having a central node that can be used to link to another communications systems. Further, a branch node that is connected to the central node can use the full bandwidth of the connection (e.g., 100 megabits) between it and the central node. That is, a branch node does not need to share any bandwidth between itself and the central node.
  • the star topology has the advantage of providing full bandwidth between a branch node and the central node. However, it uses a greater amount of transmission media (e.g., fiber optic cable) than a ring configuration.
  • transmission media e.g., fiber optic cable
  • TDM time-division multiplexing
  • WDM wavelength division multiplexing
  • FIG. 1 provides an example of a ring network configuration that uses TDM.
  • LANs 112, 114, 116 and 118 are interconnected via ring network 104 and TDMs 102.
  • TDM 102 is a time division multiplexer such as a Synchronized Optical Network (SONET) device that is capable of transmitting a packet on ring network 104 in a given time slot.
  • SONET Synchronized Optical Network
  • the total amount of ring network 104's bandwidth is divided into time slots such that each of LANs 112, 114, 116 and 118 share ring network 104's bandwidth. That is, each is able to use l/4th of the ring network 104's bandwidth.
  • Uplink 106 is a node on ring network 104 that can be used to transmit and /or receive signals to /from an external communications system.
  • TDM TDM division multiplexing-to-emitter-to-emitter-to-emitter-to-emitter-to-emitter-to-emitter-to-emitter-to-emitter-to-emitter-to-emitter-to-emitter-to-emitter-to-emitter-to-emitter-to-emitter-to-emitter-to-emitter-to-Os channels.
  • each channel is assigned a particular channel wavelength. This allows multiple signals (each at a different wavelength) to be carried on the same transmission medium.
  • multiple optical channels can be used with fiber optic cable to transmit multiple signals on the same cable.
  • Each signal channel operates at the network's full bandwidth.
  • a node can use the full bandwidth of the network by sending information one of these signal channels.
  • the channels are multiplexed at a transmitting end and transmitted to a receiving end where they are demultiplexed into individual signals.
  • the transmitting and receiving ends must be tuned to the same wavelengths to be able to communicate. That is, the transmitting and receiving ends use a device such as an add/drop multiplexer to transmit /receive a fixed signal channel.
  • an optical add /drop multiplexer is used at the transmitting and receiving ends to generate a fixed wavelength (e.g. using lasers) and to receive a fixed wavelength.
  • a fixed wavelength e.g. using lasers
  • Existing systems have as many as 16-40 signal channels. While not commercially available to date, this has been extended to as many as 100 signal channels on a single fiber.
  • Figure 2 provides an example of a ring network using WDM.
  • Signal channel 216 of ring network 204 is used by LANs 206 to communicate.
  • Signal channel 218 is used by LANs 208 to communicate.
  • the connections via LAN 204 are fixed point-to-point connections.
  • WDMs 226 are capable of generating and receiving a fixed wavelength via signal channel 216.
  • WDMs 228 are capable of generating and receiving a fixed wavelength via signal channel 218.
  • WDMs 226 are not capable of generating or receiving signals on signal channel 218, nor are WDMs 228 capable of generating or receiving signals on signal channel 216.
  • Variable add/ drop multiplexers provide a possible alternative to fixed add /drop multiplexers to allow a source or destination node to generate or receive different wavelengths.
  • a variable wavelength laser may be used on one node to generate a wavelength that can be received by a fixed wavelength receiver on another node.
  • a source node tunes its wavelength laser to the destination node's wavelength to generate a signal that can be received by the destination nodes fixed wavelength receiver.
  • a system and method of simulating a star network topology on a ring network is described.
  • Embodiments of the invention make use of a ring topology in combination with wavelength division multiplexing (WDM).
  • WDM wavelength division multiplexing
  • a virtual star network is created on the physical ring configuration to create a central node for connection to external destinations (e.g., another communication system or node).
  • Each node on the network is assigned one or more signal channels.
  • a mechanism such as an add /drop multiplexer is used to generate and receive signals via a given signal channel.
  • Branch nodes transmit on one or more signal channels to a centralized node which analyzes the information and forwards it to the destination on the network or to an external destination.
  • Embodiments of the invention comprise a system having a central node that is capable of receiving and generating on each of the signal channels used by the network nodes.
  • the central node Upon receipt of a signal, the central node analyzes the signal to determine its destination. Where the signal is intended for a node of the network, the central node generates a signal having a wavelength of the destination node. Where the signal is intended for a destination outside the network, the central node transmits the signal to the external destination via one or more of the destination's signal channels.
  • an add /drop multiplexer is used to generate and /or receive signals on each of its assigned signal channels.
  • Embodiments of the invention implement a recovery plan to ensure that information may be transmitted via the network in the event of a break in the transmission media.
  • the recovery plan at least doubles the amount of bandwidth that is available from existing recovery approaches while still ensuring that information can reach its destination.
  • the recovery approach uses two virtual star networks that are interconnected to allow information to cross-over between the virtual star networks. Thus, when information cannot reach its destination via the virtual star network on which it resides, the information can be transferred to the other virtual star network for transmission.
  • Figure 1 provides an example of a ring network configuration that uses TDM.
  • Figure 2 provides an example of a ring network using WDM.
  • Figure 3A provides an example of a virtual star network according to one or more embodiments of the invention.
  • Figure 3B provides another illustration of the virtual star topology according to one or more embodiments of the invention.
  • FIG. 4 provides a block overview of central node 302 according to an embodiment of the invention.
  • Figure 5 provides an example of external links accessible via a central node according to one or more embodiments of the invention.
  • Figure 6 provides a process flow for transmitting a packet using the virtual star topology according to one or more embodiments of the invention.
  • Figure 7 provides an example of two virtual star networks interconnected via a single central node according to one or more embodiments of the invention.
  • Figure 8 provides an illustration of a recovery configuration according to an embodiment of the invention.
  • One or more embodiments of the invention simulate a star network topology (i.e., virtual star network) using a ring network configuration.
  • the virtual star network comprises at least one central node and at least one branch node.
  • the virtual star network topology uses wavelength division multiplexing (WDM) such that multiple transmission channels (or wavelengths) may be established on a single fiber optic cable.
  • WDM wavelength division multiplexing
  • Figure 3A provides an example of a virtual star network according to one or more embodiments of the invention.
  • Branch nodes 304 and central node 302 are interconnected via virtual star network 340 whose transmission media (e.g., fiber optic cable) is in a physical ring configuration.
  • Each of branch nodes 304 is capable of generating optical signals using one or more wavelengths that are separate from the one or more wavelengths generated by the other of branch nodes 304. Therefore, the same fiber transmission media can be used to simultaneously transmit signals between branch nodes 304 and central node 302 on separate signal channels.
  • each of branch nodes 304 comprise a fixed optical add /drop multiplexer capable of generating and receiving a fixed set of optical signal for transmission on the signal channels.
  • a variable optical add /drop multiplexer can be used to transmit and receive optical signals of variable wavelengths. Any of the currently available optical add /drop multiplexers may be used with embodiments of the invention.
  • the signals that are received on signal channels of transmission media 306 are demultiplexed into individual signals that may be analyzed by central node 302 to determine the destination of the signal.
  • branch nodes 304 can perform the analysis and include a destination tag in the transmission to (e.g., a packet) identify the destination. If the destination is one of branch nodes 304, central node 302 forwards the signal using one or more signal channels of the destination branch node.
  • Central node 302 is capable of forwarding a transmission to an external destination such as another communication system (e.g., an external LAN or the Internet). In this case, central node 302 forwards the transmission via link 318 to its external destination. Similarly, central node 302 can receive external signals via link 318 that may be forwarded to branch nodes 304. Central node 302 forwards an external signal to the intended destination using one or more signal channels associated with the destination branch node.
  • an external destination such as another communication system (e.g., an external LAN or the Internet).
  • central node 302 forwards the transmission via link 318 to its external destination.
  • central node 302 can receive external signals via link 318 that may be forwarded to branch nodes 304.
  • Central node 302 forwards an external signal to the intended destination using one or more signal channels associated with the destination branch node.
  • each of branch nodes 304 can communicate at different wavelengths at the full bandwidth of virtual star network 340. This is in contrast to time division multiplexing (TDM) that limits "n" branch nodes to "1/nth" of the bandwidth of network (i.e., each of branch nodes 304 would be limited to 1/4 of the total transmission bandwidth).
  • TDM time division multiplexing
  • each of branch nodes 304 in the virtual star topology communicates with central switch 302 using the total bandwidth of virtual star network 340.
  • a signal can travel past uninvolved branch nodes (i.e., those of branch nodes 304 that are not the intended destination branch node) to the destination branch.
  • Figure 3B provides another illustration of virtual star network 340 according to one or more embodiments of the invention.
  • Virtual star network 340 of Figure 3A is shown in Figure 3B as network 300 in its actual ring or loop configuration.
  • Branch nodes 310A-310D comprise one or more fixed add/drop multiplexer capable of generating and receiving one or more signal wavelengths that are unique as to the other branch nodes 310A-310D.
  • an add/drop multiplexer model WD1515-AD1 from JDS Fitel Inc., Nepean, Ontario, Canada may be used with branch nodes 310A-310D in one or more embodiments of the invention.
  • Other add/drop multiplexers may also be used.
  • Branch nodes 310A-310D may act as a link between network 340 and another communication system such as a local area network, for example, via lines 312A-312D and 314A-314D.
  • network 300 is a metro-ring that connects buildings within a given geographic area
  • branch nodes 310A-310D link LANs within these buildings to the metro-ring.
  • a LAN in one building can be dynamically connected to a LAN in another building using the variable connection capabilities of network 300.
  • branch node 310A When information is received via line 312 A for transmission via network 300 to another LAN, for example, branch node 310A generates a optical signal having a wavelength associated with branch node 310 A and adds the signal via line 316A onto network 300.
  • the signal generated by branch node 310A travels, via one of branch node 310A's signal channels, at the full bandwidth of network 300, past branch nodes 316B-316D to central node 302.
  • Central node 302 receives the signal as well as those signals generated by branch nodes 310B-310D.
  • the signal generated by branch node 310A is separated from the other signals and analyzed by central node 302 to determine its destination.
  • central node 302 forwards the signal to its destination using one or more of the destination node's signal channels. If, for example, central node 302 determines that the signal's destination is branch node 310C, central node 302 generates a signal on a signal channel (i.e., at a given wavelength) assigned to branch node 310C.
  • the signal is transmitted via network 300 at full bandwidth past branch nodes 310A-310B to branch node 310C.
  • central node 302 uses uplink connection 318 to forward the information to its external destination.
  • Central node 302 is capable of generating and receiving each of the wavelengths that may be generated /received by branch nodes 310A-310D, analyzing addresses contained in the information received from branch nodes 310A-310D and forwarding the information to its intended destination.
  • branch nodes 310A-310D there is no need for any of branch nodes 310A-310D to use variable add/drop technology.
  • FIG. 4 provides a block diagram of central node 302 according to an embodiment of the invention.
  • central node 302 may be configured to accommodate more or less than four signal channels.
  • central node 302 may accommodate one signal channel for each branch node.
  • more than one signal channel may be assigned to a branch node.
  • Demultiplexer 404 of central node 302 separates the signal wavelengths received on signal channels of network 300 into individual signals.
  • Demultiplexer 404 may be, for example, a JDS Fitel demultiplexer model WD15016-D1. It should be apparent that other demultiplexers may also be used with embodiments of the invention.
  • Demultiplexer 404 forwards the individual signals 406A-406D to switch 412 via ports 408A-408D, respectively.
  • the signals that are transmitted via network 300 represent a packet of information that contains address data.
  • Switch (or router) 412 is configured to analyze a packet received via one of ports 408A-408D to determine the destination of the information.
  • Switch 412 is configured to analyze the header information, determine the destination of the packet and forward the information to a output port of switch 412.
  • Switch 412 may be, for example, a share switch from PMC-Sierra, Inc. located in Burnaby, British Columbia, Canada. However, it should be apparent that other switches may be used with embodiments of the invention.
  • switch 412 outputs the signal to multiplexer 424 via ports 418A-418B.
  • Each of ports 418A-418D is connected to a wavelength transmitter of multiplexer 424.
  • the wavelength transmitter that receives a signal transmits a signal at the destination's wavelength via network 300 to its destination.
  • Multiplexer 424 multiplexes the individual signals received from switch 412 at their respective wavelengths onto network 300.
  • Multiplexer 424 may be, for example, a multiplexer model WD15016-M1 available from JDS Fitel. It should be apparent that other multiplexers may also be used.
  • branch node 310A For example, if branch node 310A generates a packet specifying branch node 310C as its destination node, the packet is transmitted via one of branch node 310A's signal channels on network 300 to central node 302.
  • the signal is received by demultiplexer 404 of central node 302.
  • ports 408A-408D and 418A-418D are associated with the signal channels of branch nodes 310A-310D of Figure 3B, respectively.
  • Demultiplexer 404 separates out the signal received from branch node 310A and sends the packet that is represented by the signal to switch 412 via port 408A.
  • Switch 412 examines the packet to determine that branch node 310C is the packet's destination. Switch 412 outputs the packet on port 416C that corresponds to branch node 3 IOC. Multiplexer 424 generates a signal for transmission via network 300 that corresponds to a signal channel of branch node 310C. Like a star topology, the signals that are transmitted between branch node 310A and 310C use network 300's full bandwidth. Further, as with a star topology, the signals are passed through a central node (e.g., central node 302).
  • a central node e.g., central node 302
  • Central node 702A can provide a link to the World Wide Web (WWW), or Internet, for example.
  • WWW World Wide Web
  • a branch node that is connected to central node 702 A can communicate (e.g., upload or download) information with the Internet via link 706.
  • branch node 512 of network 500A can transmit and/or receive information from the Internet via central node 502A.
  • Branch node 510 can be linked to central node 502A (via link 508) to communicate with a branch that is connected to central node 502B (e.g., branch node 514) as well as to the Internet.
  • Central node 502A is connected to central node 502B via link 504.
  • a branch node that resides on network 500 A can communicate with a branch node that resides on network 500B.
  • branch node 512 of network 500A can transmit a packet using one or more of its signal channels to central node 502A which determines that the packet is destined for branch node 514 of network 500B.
  • Central node 502A forwards the packet to central node 502B via link 504.
  • Central node 502B transmits the packet via one of branch node 514's signal channels to branch node 514.
  • branch nodes that reside on separate virtual star networks e.g., branch nodes 512 and 514) may use the same signal channels.
  • transmission of information from one branch node on the network to another branch node is performed using the central node according to one or more embodiments of the invention.
  • the information that is to be transmitted is contained in a packet that further contains addressing information. Examples of protocols that may be used to generate packets are Asynchronous Transfer Mode (ATM) or Internet Protocol (IP).
  • ATM Asynchronous Transfer Mode
  • IP Internet Protocol
  • the header and addressing information is determined according to specific protocol used.
  • a branch node may specify a destination address as a tag thereby eliminating the need for the central node to determine the destination. In this case, the addressing information is contained within the tag.
  • Figure 6 provides a process flow for transmitting a packet using the virtual star topology according to one or more embodiments of the invention.
  • Figure 6 assumes that the central node identifies the destination (i.e., the source node does not provide a destination tag).
  • central node 302 When the central node (e.g., central node 302) is initiated, central node 302 is programmed or in some way learns which header addresses are associated with which branch nodes. For example, central node 302 can retrieve a lookup table that associates header addresses with their respective branch nodes. Similarly, branch node 302 is aware of the input/output ports (e.g., ports 408A-408D and 418A-418D, respectively).
  • a branch node (e.g., branch node 310A) transmits a packet using one or more of its signal channels.
  • central node 302 separates the branch node 310A's signal into an individual signal. It is possible for branch node 310A to be assigned more than one wavelength. In this case, branch node 310A may send the packet using more than one signal channel. This increases the amount of bandwidth that is available to a branch node. If, for example, branch node 310 uses two signal channels to send the information, the amount of bandwidth that is available to branch node 310 is doubled.
  • the central node analyzes the packet's addressing information.
  • a determination is made as to whether the destination is on the network. If not, processing continues at step 614 to forward the packet to its destination via the external link (e.g., external link 318). If the destination is on the network, central node 302 transmits the packet using one or more of the signal channels (or wavelengths) associated with the destination branch node. In either case, processing of a packet ends at step 612.
  • Figure 5 provided one example of two interconnected virtual star networks using two separate central nodes.
  • Figure 7 provides an example of two virtual star networks interconnected via a single central node according to one or more embodiments of the invention.
  • Central node 702 comprises two instances of central node 302. One instance of central node 302 handles the traffic transmitted on network 700A while the other handles the traffic that is transmitted on network 700B.
  • Central node 702 comprises two of switch 412 (e.g., switches 732A and 732B), demultiplexer 404 and multiplexer 424. As previously described, demultiplexer 404 and multiplexer 424 are connected to switches 732A and 732B via at least one port (e.g., ports 408A-408D and 418A-418D). Link 704 links the instances of switches 732A and 732B. Switches 732A and 732B use different instances of demultiplexer 404 and multiplexer 424 that are connected to separate networks (i.e., networks 700 A and 700B). Therefore, it is possible to use the same signal channels for two nodes where each node resides on a different network (i.e., where one node resides on network 700A while the other resides on network 700B).
  • switch 412 e.g., switches 732A and 732B
  • demultiplexer 404 and multiplexer 424 are connected to switches 732A and 732B via at least one port
  • the packet generated by branch node 710B is forwarded to switch 732 A.
  • Switch 732A analyzes the packet's header information to determine packet's destination.
  • the packet sent by branch node 710B is intended for branch node 760B of network 700B, for example.
  • Switch 732A forwards the packet to switch 732B via link 704.
  • Switch 732B forwards the packet to the instance of multiplexer 424 associated with switch 732B.
  • Switch 732B's multiplexer 424 generates one or more signals that represent the packet using one or more of branch node 760B's signal channels.
  • the signals that are generated by switch 732B's multiplexer 424 are transmitted via network 700B to branch node 760B.
  • branch node 760B's signal channels may be the same as branch node 710B.
  • the packet is intended for a node that is positioned at the six o'clock position on the rings and the break occurs at the two o'clock position, the packet that is transmitted in the clockwise direction is unable to reach the node. However, the packet that is transmitted in the counterclockwise direction is able to reach the node.
  • Embodiments of the invention implement a recovery plan that does not require the transmission of redundant information. This allows both rings to be used to double the amount of bandwidth that is available for transmission when there is no break, and ensures that information can reach its destination when a break occurs.
  • Figure 8 illustrates a recovery configuration according to an embodiment of the invention.
  • Branch nodes 810A-810B are connected to ring 800A via lines 816A-816B as well as being connected to ring 800B via lines 820A-820B.
  • Central node 802A is located on ring 800A and central node 802B is located on ring 800B.
  • Link 828 exists between central nodes 802 A and 802B.
  • Packets are sent on ring 800A in the counterclockwise direction while packets on ring 800B are sent in the clockwise direction.
  • Branch nodes 810A and 810B can communicate via either or both of rings 800A and 800B.
  • branch node 810A sends a packet via line 820A on ring 800B.
  • Central node 802B receives the packet and determines that it is destined for branch node 810B. Absent break 830, central node 802B may forward the packet to branch node 810B via either of rings 800A or 800B.
  • a packet destined for branch node 810B sent by central node 802B via network 800B cannot reach branch node 810B.
  • central node 802B can send the packet to central node 802A which forwards the packet to branch node 810B via ring 800A and line 816B.

Abstract

Cette invention concerne un système et un procédé de simulation d'une topologie de réseau en étoile sur un réseau en anneau (300). Les modes de réalisation de la présente invention mettent en oeuvre une topologie en anneau en combinaison avec le multiplexage par répartition en longueur d'onde (MRL) pour élaborer un réseau en étoile virtuel, possédant un noeud central (302) destiné à effectuer la connexion avec des destinations externes. Les noeuds de ramification (310A-310D) émettent, sur un ou plusieurs canaux de signalisation, vers le noeud central (302) qui analyse les informations et les achemine vers une destination à l'intérieur du réseau ou à une destination externe. Les modes de réalisation de la présente invention concernent la mise en place d'une procédure de récupération assurant la transmission des informations par le réseau dans le cas d'une coupure à l'intérieur des moyens de transmission. La procédure de récupération permet d'au moins doubler la largeur de bande tout en garantissant le transfert des informations vers leur destination.
PCT/US1999/027066 1999-01-16 1999-11-12 Systeme et procede de simulation d'une topologie de reseau en etoile WO2000042739A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AU17263/00A AU1726300A (en) 1999-01-16 1999-11-12 System and method of simulating a star network topology

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US23213299A 1999-01-16 1999-01-16
US09/232,132 1999-01-16

Publications (1)

Publication Number Publication Date
WO2000042739A1 true WO2000042739A1 (fr) 2000-07-20

Family

ID=22871989

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US1999/027066 WO2000042739A1 (fr) 1999-01-16 1999-11-12 Systeme et procede de simulation d'une topologie de reseau en etoile

Country Status (2)

Country Link
AU (1) AU1726300A (fr)
WO (1) WO2000042739A1 (fr)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1703677A2 (fr) * 2005-03-16 2006-09-20 Nec Corporation Système de terminaison de ligne d'accès, unité de terminaison de ligne d'accès et méthode de commande de transmission
WO2010060288A1 (fr) * 2008-11-03 2010-06-03 华为技术有限公司 Procédé, dispositif et système de topologie d’un réseau
CN103176993A (zh) * 2011-12-21 2013-06-26 北京神州绿盟信息安全科技股份有限公司 一种内容呈现设备和方法
CN104346170A (zh) * 2014-10-15 2015-02-11 浪潮(北京)电子信息产业有限公司 一种基于画布Canvas的拓扑图生成方法及装置

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5612805A (en) * 1994-06-07 1997-03-18 Alcatel Cit Add-drop optical spectrum-division multiplexer
US5986783A (en) * 1997-02-10 1999-11-16 Optical Networks, Inc. Method and apparatus for operation, protection, and restoration of heterogeneous optical communication networks

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5612805A (en) * 1994-06-07 1997-03-18 Alcatel Cit Add-drop optical spectrum-division multiplexer
US5986783A (en) * 1997-02-10 1999-11-16 Optical Networks, Inc. Method and apparatus for operation, protection, and restoration of heterogeneous optical communication networks

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1703677A2 (fr) * 2005-03-16 2006-09-20 Nec Corporation Système de terminaison de ligne d'accès, unité de terminaison de ligne d'accès et méthode de commande de transmission
EP1703677A3 (fr) * 2005-03-16 2006-10-18 Nec Corporation Système de terminaison de ligne d'accès, unité de terminaison de ligne d'accès et méthode de commande de transmission
WO2010060288A1 (fr) * 2008-11-03 2010-06-03 华为技术有限公司 Procédé, dispositif et système de topologie d’un réseau
CN101729353B (zh) * 2008-11-03 2012-04-04 华为技术有限公司 网络拓扑布局的方法、装置及系统
CN103176993A (zh) * 2011-12-21 2013-06-26 北京神州绿盟信息安全科技股份有限公司 一种内容呈现设备和方法
CN103176993B (zh) * 2011-12-21 2016-08-24 北京神州绿盟信息安全科技股份有限公司 一种内容呈现设备和方法
CN104346170A (zh) * 2014-10-15 2015-02-11 浪潮(北京)电子信息产业有限公司 一种基于画布Canvas的拓扑图生成方法及装置

Also Published As

Publication number Publication date
AU1726300A (en) 2000-08-01

Similar Documents

Publication Publication Date Title
US6233074B1 (en) Ring networks utilizing wave division multiplexing
US6999461B2 (en) Routing schemes for packet switching networks
US6850708B2 (en) Distributed intelligence wavelength division multiplexed network
CA2314322C (fr) Commutateur optique et protocoles a utiliser avec ce commutateur
US6826368B1 (en) Wavelength division multiplexing (WDM) with multi-frequency lasers and optical couplers
US7733812B2 (en) Method for enabling multipoint network services over a ring topology network
EP1348265B1 (fr) Maintien de la qualite du trafic de paquets dans un reseau optique en cas de panne d'une liaison optique
US6417944B1 (en) Asynchronous transfer mode switch utilizing optical wave division multiplexing
CA2343576A1 (fr) Plan de commande de supervision de reseaux a routage par longueur d'onde
JP2002521860A (ja) 光タグスイッチングを使用した高スループットで低レイテンシの次世代インターネットネットワーク
US20060210274A1 (en) Apparatus For and Method of MAC Based Transmission in WDM Optical Ring Networks
CA2317972A1 (fr) Systeme et methode de routage reparti au niveau des paquets dans un reseau optique en anneau
US6141126A (en) Wave division multiplexing based optical switch
US6473397B1 (en) Add/drop multiplexer and method, and Bi-directional line switcher ring featuring such multiplexers
EP1897401B1 (fr) Decouverte d'un element de reseau adjacent dans un plan de donnees de reseau
US20040141758A1 (en) System and method for providing multiple services to a destination via a fiber optic link
US20040213572A1 (en) Optical ring network for burst data communication
EP0407078B1 (fr) Agencement de connection efficace et procédé de communication pour réseaux à bonds multiples
WO2000042739A1 (fr) Systeme et procede de simulation d'une topologie de reseau en etoile
JP3442840B2 (ja) 光通信システム
Modiano et al. Architectural considerations in the design of WDM-based optical access networks
Salvador et al. An all-optical WDM packet-switched network architecture with support for group communication
US6985443B2 (en) Method and apparatus for alleviating traffic congestion in a computer network
JP3597818B2 (ja) 光通信システム
US7486677B1 (en) Technique for providing inter-nodal communications in a photonics network

Legal Events

Date Code Title Description
ENP Entry into the national phase

Ref country code: AU

Ref document number: 2000 17263

Kind code of ref document: A

Format of ref document f/p: F

AK Designated states

Kind code of ref document: A1

Designated state(s): AE AL AM AT AU AZ BA BB BG BR BY CA CH CN CR CU CZ DE DK DM EE ES FI GB GD GE GH GM HR HU ID IL IN IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MA MD MG MK MN MW MX NO NZ PL PT RO RU SD SE SG SI SK SL TJ TM TR TT TZ UA UG UZ VN YU ZA ZW

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): GH GM KE LS MW SD SL SZ TZ UG ZW AM AZ BY KG KZ MD RU TJ TM AT BE CH CY DE DK ES FI FR GB GR IE IT LU MC NL PT SE BF BJ CF CG CI CM GA GN GW ML MR NE SN TD TG

121 Ep: the epo has been informed by wipo that ep was designated in this application
REG Reference to national code

Ref country code: DE

Ref legal event code: 8642