Patent ID: 7742434

Claim:
A local area network comprising: a plurality of modules interconnected by a plurality of point-to-point links to form a first daisy chain, in which all of the modules are interconnected, and second and third daisy chains, in each of which less than all of the plurality of modules are interconnected so that each of the second and third daisy chains is partially redundant to the first daisy chain, each of the plurality of modules including a multi-port switch capable of connecting the module, through first and second ports, to two of the plurality of modules preceding the module in the network, and, through third and fourth ports, to two of the plurality of modules following the module in the network, the plurality of modules comprising: a first end module, a second end module and a plurality of modules intermediate the first and second end modules, the first end module being connected to two intermediate modules following the first end module in the network by two point-to-point links extending directly between a port of the multi-port switch of the first end module and a port of each of the respective multi-port switches of the two following intermediate modules, the second end module being connected to two intermediate modules preceding the second end module in the network by two point-to-point links extending directly between a port of the multi-port switch of the second end module and a port of each of the respective multi-port switches of the two preceding intermediate modules, each of the plurality of intermediate modules being connected (a) to two modules preceding and at least one module following the module in the network by at least three point-to-point links extending respectively between at least three ports of the multi-port switch of the intermediate module and a port of each of the respective multi-port switches of the two preceding and at least one following modules, and/or (b) to two modules following and at least one module preceding the intermediate module in the network by at least three point-to-point links extending respectively between at least three ports of the multi-port switch of the intermediate module and a port of each of the respective multi-port switches of the two following and at least one preceding modules, whereby the first and second or third daisy chains of modules can be extended and/or each of the plurality of modules can fail and/or be removed, one at a time, from the network and replaced without affecting the operation of the network.