摘要:
A LAN interconnect device includes a plurality of Frame Processing Units (FPUs) for coupling each port of the device to a switch fabric. Each one of the Frame Processing Units includes an input section with input logic which prepares LS Headers and appends each one to a block of the frame as the block is forwarded to the switch fabric. The FPU, also, includes an output section with copy logic for copying and assembling frames to be forwarded to devices connected to the port. The copy decision is based upon the LS Header and configuration information in the port.
摘要:
A method for forwarding data packets to one of a plurality of servers comprising receiving a data packet from a source, at a data packet forwarding device having a plurality of ports, performing a hashing function using a unique component of the data packet as a seed value for the hash, generating a hash value using the hashing function, looking up a table for an address of one of the plurality of servers using the hashed value as an index to the table, and forwarding the data packet to a server corresponding to the address.
摘要:
A method of alleviating network congestion in an emulated Local Area Network (ELAN) within an Asynchronous Transfer Mode (ATM) network is implemented. The method mitigates network congestion by distributing the connection times of Local Area Network (LAN) Emulation Client (LEC) to an ELAN over random periods of time. When a LAN Emulation Server (LES) or Broadcast and Unknown Server (BUS) attempts to build point-to-multipoint connections to the LEC, it issues control messages to network switches. If the messages are dropped or rejected the LES or BUS recognizes the network is in a congested state and randomly retries to attempt connection.
摘要:
To ensure a LES issues address resolution responses when necessary, an association between a MAC/ATM address pair and an intersubnet shortcut virtual channel connection (VCC) is registered. When the LES receives a first data frame being sent from a first station to a second station, with the second station having a MAC address associated with a shortcut VCC, a second data frame is created. The second data frame has as a source address the MAC address. The second frame is sent to devices associated with the first station so that the devices may learn the origination point for the second station and can issue messaging necessary to establish an shortcut VCC. In addition, frame loss reduction in an ATM communications network is accomplished by registering an association between a MAC address of a router associated with a MAC/ATM address pair, and a shortcut VCC. After the association is registered, a data frame being sent from a first station to a second station is received. The second station has the same MAC address as the MAC/ATM address pair. The destination MAC address of the data frame is replaced with the MAC address of the router, wherein the data frame can now be delivered. Also, a first station is prevented from having to wait to send data to a second station over a newly created shortcut VCC by registering an association between a MAC/ATM address pair and a shortcut VCC. Next, a flush request message from an edge device on an ELAN is received. The flush request has a destination ATM address equal to the ATM address of the MAC/ATM address pair. A flush response message is sent to the edge device, where upon receiving the flush response message, the edge device will start sending data from the first station to the second station over the newly created shortcut VCC.
摘要:
Provided are a method and system for achieving enhanced performance in communications involving one or more emulated networks overlaid onto at least one base network, where the emulation is performed by one or more network emulation servers-broadcast and unknown servers. The objects of the method and system are achieved via the following. Monitoring addresses of data transiting the one or more network emulation servers-broadcast and unknown servers where such monitored addresses are indicative of one or more functions provided by the one or more emulated networks. Tracking the monitored addresses. Comparing the tracked addresses, indicative of on or more functions provided by the one more emulated networks, with one or more prespecified thresholds indicative of monopolization of resources of the at least one emulated network. And, taking corrective action when the aforementioned comparing of addresses indicates that one or more entities associated with the tracked addresses are monopolizing resources of the at least one emulated network such that communications involving the at least one emulated network are enhanced.
摘要:
A network switch receives a data packet, recognizes the data packet as belonging to a given stream, and directs the data packet to a stream processing module in the network switch in response to recognizing the stream to which the packet belongs. The stream processing module further recognizes the source of the stream from which the packet was transmitted, and stores the data packet in a buffer for later transmission, as controlled by the stream processing module, to a destination for the stream. In this way, the stream may be replicated and transmitted by the stream processing module any number of times to multiple destinations in an efficient, cost-effective manner.
摘要:
A method and system for providing enhanced peer redundancy in an ATM emulated local area network (ELAN) served by a primary LAN emulation server (LES), a peer LAN emulation server, a broadcast and unknown server (BUS), and a LAN emulation configuration server (LECS). An enhanced peer redundancy virtual channel connection (VCC) is established between the primary LES/BUS and the peer LES/BUS. The primary LES/BUS and the peer LES/BUS exchange status messages every two seconds indicating the number of assigned LECs. If the primary has fewer LECs than the peer, the primary yields to the peer as the active LES/BUS. If an enhanced redundancy VCC was not established, the backup LES/BUS provides ELAN services while waiting for the primary to call to establish an enhanced redundancy VCC. If an enhanced peer redundancy VCC cannot be established, the primary attempts to establish a redundancy VCC with the peer in which the peer LES/BUS is kept in a dormant mode as long as the redundancy VCC is present. If the redundancy VCC is absent, the peer LES/BUS is activated to service the ELAN.
摘要:
A method for providing interoperability between multiple versions of LUNI within a mixed Asynchronous Transfer Mode emulated LAN is disclosed. The mixed ATM emulated LAN includes multiple LAN emulated clients (LE clients) having different versions of LAN Emulation User Network Interface (LUNI), such as a first version LUNI and a second version LUNI. The mixed ATM emulated LAN is served by a LAN Emulation Server (LES), a Broadcast and Unknown Server (BUS), and a LAN Emulation Configuration Server (LECS). When an LE Control Frame is being sent by an LE client having a second version LUNI, a determination is made as to whether or not the LE Control Frame will be received by an LE client having a first version LUNI. In response to a determination that the LE Control Frame sent by the LE client having a second version LUNI will be received by an LE client having a first version LUNI, the LE Control Frame is copied, and the copied LE Control Frame is converted to an LE Control Frame with a format that is readable by the LE client having a first version LUNI.
摘要:
A data communication network includes a network client, a network server, and a name caching entity located between the network client and the network server. The network server is coupled to the data communication network by a plurality of network adapters that each have a different network (e.g., Media Access Control (MAC)) address, but share a common logical name. The name caching entity includes a name cache, which stores the common logical name shared by the server's network adapters in association with the network address of one of the network adapters. By reference to the name cache, the name caching entity is able to convert broadcast frames to unicast frames, thereby advantageously reducing broadcast frames in the network. The name caching entity will disassociate the logical name and the network address in the name cache in response to a failure to detect a frame indicating the establishment of a session with the network server within a selected interval of transmission of a frame requesting establishment of a session with the network server. In this manner, the network client can establish a session with the network server through another network adapter in cases in which the network adapter whose network address is stored in the name cache cannot support an additional session.
摘要:
A method and system for improving communications in data communications networks which provide network emulation. The method and system accomplish their objects via communications equipment adapted to do the following: implant a number of distributed-redundant gateways in an emulated network; and dynamically assign access to operational distributed-redundant gateways. In one embodiment, the network emulation is an Asynchronous Transfer Mode Emulation Local Area Network (ATM ELAN), and the distributed-redundant gateways operate as default Internet Protocol (IP) gateway utilized by LAN Emulation Clients (LE Clients) of the ATM ELAN. Also in one embodiment, the dynamic assignment of access is done such that the data communications loading associated with the default IP gateway is distributed throughout a data communications network.