Abstract: A method for assisting media access control (MAC) address learning is disclosed. The method includes receiving, at a first provider edge (PE) device, a data packet from a core network, the data packet identifying an Ethernet Segment (ES) from which the data packet originated and identifying a first MAC address as the destination MAC address; determining, at the first PE device, whether the first PE device has an Ethernet connection in the ES identified by the data packet and whether the first PE device has learned the first MAC address; and, upon positive determination, sending an announcement message to the core network, the announcement message identifying the first MAC address.

Abstract: A computer-implemented method for assisting Ethernet Segment (ES)-aware media access control (MAC) address learning is disclosed. The method includes receiving, at a provider edge (PE) device, a data packet from a core network, the data packet identifying an ES from which the data packet originated and identifying a MAC address as a source MAC address; determining whether the PE device has an Ethernet connection in the ES identified by the data packet; and, upon positive determination, associating the MAC address identified as the source MAC address of the data packet to a bridge port, at the PE device, of the Ethernet connection in the ES identified by the data packet.

Abstract: In a network system for transporting GFP-encapsulated Fibre Channel/FICON data across a SONET/SDH transport network between two Fibre Channel/FICON ports, a transport interface for one Fibre Channel/FICON port intelligently allocates the amount of buffers for receiving Fibre Channel/FICON data from the other Fibre Channel/FICON port by determining the latency of travel across the SONET/SDH transport network. The first transport interface inserts a special latency instruction message into the Fibre Channel/FICON data before encapsulation in a GFP frame. After transport across the SONET/SDH network, the receiving second transport interface immediately sends the special latency instruction message back across the SONET/SDH transport network to the first transport interface which times the return of the special latency instruction message. From the time interval, the first transport interface can determine the latency of the SONET/SDH transport network and allocates the amount of buffers appropriately.

Abstract: A method and system for emulating an Ethernet link over a Sonet path to provide link integrity is disclosed. The method generally includes receiving an error code at a local Ethernet port upon detection of a link failure at a remote Ethernet port. The error code is received over a Sonet path in a Sonet path overhead. If the error code is still present after a specified period of time, the local Ethernet port is disabled. Methods for providing link stability and link availability are also disclosed.

Abstract: In network systems for transporting GFP-encapsulated FICON frames across a SONET/SDH transport network between FICON ports, the transport interfaces for the FICON ports operate to drop duplicate and out-of-order frames transported across the SONET/SDH network. The transmitting transport interface inserts a sequence number incremented with each FICON frame into said one or more transport frames, whereby the sequence number is used as an index for determining duplicate and out-of-order frames after transport over said SONET/SDH network. The receiving transport interface compares sequence numbers with each FICON frame to determine duplicate and out-of-order FICON frames, drops the duplicate and out-of-order FICON frames; and sends the balance of the compared FICON frames to the receiving FICON port.

Abstract: A method and system for flow control of GFP-encapsulated Fiber Channel frames over SONET/SDH transport networks is described. Transport interfaces, in the form of port cards, monitor any switch-over or error in the SONET/SDH transport network responsive to GFP out of synchronization signals; and transmit Fiber Channel Ordered Sets indicative of non-operation to it associated Fiber Channel port so that the Fiber Channel port performs link initialization and buffer credit recovery procedures with its counterpart Fiber Channel port across the SONET/SDH transport network. This speeds the recovery of the link between the two Fiber Channel ports.

Abstract: A method and system for communicating state information between a local device and a remote device across a transport network is disclosed. Each of the local and remote devices operate independently from one another and at least one of the devices is configured for one-way traffic protection. The method includes receiving a protection message comprising K-bytes from one of the local and remote devices at the other of the local and remote devices and determining based on the received K-bytes, if there is a change in state at one of the devices. If a change in state is detected, a message is sent indicating the change in state from one of the local and remote devices to the other of the local and remote devices.

Abstract: A method and system for flow control of GFP-encapsulated client data frames over SONET/SDH transport networks is described. Transport interfaces, in the form of port cards, have FIFO buffers for receiving the GFP frames. In acknowledgment of the received frames, a transmitting transport interface receives an acknowledgement in form of a returned frame sequence number tag along with the available capacity in bytes of the buffer of the receiving transport interface. With a continuous update of buffer capacity and tracking the number of bytes in transit to the receiving transport interface, the transmitting transport interface maximizes the utilization of the channel through the SONET/SDH transport network, even with dropped frames or dropped acknowledgment tags.

Abstract: A multiported LAN switch comprised of legacy local area network ports and ATM ports. Each ATM port comprising a hardware forwarding engine for bridging LAN frames from the LAN ports to the ATM port. The hardware forwarding engine converts layer 2 protocols between the dissimilar ports expediently, without requiring intervention by a microprocessor. A substantial performance gain is attained compared to microprocessor controlled format converters. Both LAN emulation and virtual LANs are supported.

Abstract: A method and system for emulating an Fibre Channel link over a SONET transport path by which Fibre Channel data is transported across the SONET/SDH transport path. To provide link integrity, techniques to handle link failures from a Fibre Channel element to its associated Fibre Channel port, or of the SONET/SDH network linking Fibre Channel ports include transmitting error condition codes over the SONET/SDH transport path overhead to a remote Fibre Channel transport interface so that the Fibre Channel link from the remote Fibre Channel transport interface to the associated remote Fibre Channel port is disabled. Timing the length of failures and return of operation of the failed links is used to handle transient conditions and to avoid link bouncing.

Abstract: A multiported LAN switch comprised of legacy local area network ports and ATM ports. Each ATM port comprising a hardware forwarding engine for bridging LAN frames from the LAN ports to the ATM port. The hardware forwarding engine converts layer 2 protocols between the dissimilar ports expediently, without requiring intervention by a microprocessor. A substantial performance gain is attained compared to microprocessor controlled format converters. Both LAN emulation and virtual LANs are supported.

Abstract: A multiported LAN switch comprised of legacy local area network ports and ATM ports. Each ATM port comprising a hardware forwarding engine for bridging LAN frames from the LAN ports to the ATM port. The hardware forwarding engine converts layer 2 protocols between the dissimilar ports expediently, without requiring intervention by a microprocessor. A substantial performance gain is attained compared to microprocessor controlled format converters. Both LAN emulation and virtual LANs are supported.

Abstract: A multiported LAN switch comprised of legacy local area network ports and ATM ports. Each ATM port comprising a hardware forwarding engine for bridging LAN frames from the LAN ports to the ATM port. The hardware forwarding engine converts layer 2 protocols between the dissimilar ports expediently, without requiring intervention by a microprocessor. A substantial performance gain is attained compared to microprocessor controlled format converters. Both LAN emulation and virtual LANs are supported.

Abstract: A multiported LAN switch comprised of legacy local area network ports and ATM ports. Each ATM port comprising a hardware forwarding engine for bridging LAN frames from the LAN ports to the ATM port. The hardware forwarding engine converts layer 2 protocols between the dissimilar ports expediently, without requiring intervention by a microprocessor. A substantial performance gain is attained compared to microprocessor controlled format converters. Both LAN emulation and virtual LANs are supported.

Abstract: A multiported LAN switch comprised of legacy local area network ports and ATM ports. Each ATM port comprising a hardware forwarding engine for bridging LAN frames from the LAN ports to the ATM port. The hardware forwarding engine converts layer 2 protocols between the dissimilar ports expediently, without requiring intervention by a microprocessor. A substantial performance gain is attained compared to microprocessor controlled format converters. Both LAN emulation and virtual LANs are supported.

Abstract: A method and system are provided for increasing processing efficiency associated with data frames transiting a network node having multiple ports. The method and system accomplish their objects via the following. A data frame having a header and data is received. An associated pointer for at least one portion of the received data frame is provided. The associated pointer is provided by segmenting each received data frame into parts, and associating with each segmented part a pointer. Thereafter, a portion of the received data frame is modified independent of other portions of the received data frame via utilization of given one or more of the associated pointers. Additionally, one or more copies of a portion (which can include the whole) of the received data frame is constructed by recalling each segmented part associated with one or more selected ones of the associated pointers. Furthermore, a determination is made as to whether the received header indicates unicast or multicast.

Abstract: A method and system are provided for enabling simultaneous cut-through and store-and-forward transmission of frames in high speed network devices. A Buffer Parameter Vector chains multiple frame buffers together. Frame Parameter Vectors created for each unique version of a frame are used to manage frames as they flow through the network device. Cut-through/store-and-forward decision logic determines whether frames can be transmitted by cut-through or store-and-forward. Multiple unique frames or copies of a frame that are to be transmitted store-and-forward have their Frame Parameter Vectors chained together by pointers. The cut-through/store-and-forward decision logic steps through the chain of Frame Parameter Vectors resulting in the frames associated with each Frame Parameter Vector being transmitted.

Abstract: A multiported LAN switch comprised of legacy local area network ports and ATM ports. Each ATM port comprising a hardware forwarding engine for bridging LAN frames from the LAN ports to the ATM port. The hardware forwarding engine converts layer 2 protocols between the dissimilar ports expediently, without requiring intervention by a microprocessor. A substantial performance gain is attained compared to microprocessor controlled format converters. Both LAN emulation and virtual LANs are supported.

Abstract: A memory interface for multi-port access to a memory unit, such as a static random-access memory (SRAM) device. The memory interface, which is generally adapted for a local area network (LAN) forwarding engine, provides single port read/write access to SRAM device, and arbitrates requests from the access interfaces to allocate bandwidth of the SRAM device among the requests. One embodiment allocates at least 50% of the bandwidth to a peripheral component interface (PCI) bus target interface and a PCI bus master interface, collectively. The arbitration logic may include a plurality of bandwidth control registers associated with respective access interfaces used to determine a permitted amount of bandwidth that an access interface is to have, wherein a request from an access interface is masked based on a value in its associated bandwidth control register. Arbitration can further allocate bandwidth using time division multiplexing.