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: 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 Fibre 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 Fibre Channel Ordered Sets indicative of non-operation to it associated Fibre Channel port so that the Fibre Channel port performs link initialization and buffer credit recovery procedures with its counterpart Fibre Channel port across the SONET/SDH transport network. This speeds the recovery of the link between the two Fibre Channel ports.

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 to provide link integrity is disclosed. 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 are described. 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 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.