Methods and apparatus for switching
Fiber Channel
Arbitrated Loop Systems is provided between a plurality of
Fiber Channel Loop devices. In one aspect of the invention, the
system switches based at least in part on
arbitrated loop primitives. An exemplary interconnect
system may include a first port and a second port, both including port logic to monitor certain
arbitrated loop primitives, a
connectivity apparatus, a
route determination apparatus including a
routing table consisting of ALPA addresses and their associated ports, the
route determination apparatus coupled to each port and the
connectivity apparatus, where the
connectivity apparatus creates paths between the ports based on
arbitrated loop primitives. In one embodiment, the connectivity apparatus is a
crossbar switch. Examples of the arbitrated loop primitives that cause the switch to create paths between ports includes one or more of the following: ARB, OPN and CLS. In yet other aspects, the
system ensures device access fairness through one or more techniques, including a rotating priority system, a counter to count the number of OPNs, especially sequential OPNs, and / or priority based on
port type. Device
zoning may be implemented. In one implementation, the system includes
trunking such that frames may be transferred on multiple ports.