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 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: Provided are a method and system for achieving enhanced performance in communications between a plurality of emulated networks overlaid onto at least one base network, wherein the communications involve one or more source route bridges. The method and system accomplish their objects via the following. Determining when communication is to occur, through the one or more source route bridges, and between at least two entities where a first of the at least two entities is a member of a first emulated network and where a second of the at least two entities is a member of another of the plurality of emulated networks. Informing the at least one of the at least two entities of one or more addresses consonant with the protocols of the at least one base network wherein the one or more addresses identify one or more base network entities closely correspondent to at least one of the at least two entities.

Abstract: An ATM communications network with several ELANs allows steady-state data to be passed between ATM attached devices which bypasses intermediate LECs and bridges. Connected to the ATM communications network is a bridge unit which includes a bridge and associated LECs. Also, an origination ATM attached device and a destination ATM attached device are attached to the ATM communications network via a first by a first ELAN and a second ELAN, respectively. The origination ATM attached device sends a request for an ATM address associated with the destination ATM attached device to the bridge, via the first ELAN. After some processing, the bridge returns the ATM address associated with the destination ATM attached device to the origination ATM attached device. This allows the origination ATM attached device to establish a shortcut VCC with the destination ATM attached device using the ATM address associated with the destination ATM attached device, thereby bypassing intermediate bridges and LECs.