Patent ID: 6879559

Claim:
A communication network comprising N substantially identical working line circuit cards, namely working line circuit cards w 1 , w 2 , . . . , wi, . . . , w(N+1), w(N) and M protect line circuit cards, namely protect line circuit cards p 1 , p 2 , . . . , pi, . . . p(M−1), p(M), each substantially identical with said working line circuit card, wherein N and M is each a positive integer such that M is smaller than N; said line circuit cards having a working configuration such that each of said working line circuit cards w 1 , w 2 , . . . , wi, . . . , w(N−1), w(N) is connected in series into one of N respective separate data paths d 1 , d 2 , . . . , di, . . . , d(N−1), d(N) independent from any other of said working line circuit cards and having a protection switch configuration differing from said working configuration such that in at least one of said separate data paths di said working line circuit card wi is replaced by said substantially identical protect line circuit card pi, wherein said working line circuit cards and said protect line circuit cards are configured to extract packet information from memory and assemble it into chunk payloads; wherein said data paths comprise solid state switches, such that said line circuit cards are connected into said data paths through said solid state switches; and wherein each of said data paths comprises two paired duplicate interface circuit cards differing in structure from said line circuit cards, said duplicate interface card configured to perform integrity checks on incoming information packets and to extract said information packets from a frame, each said duplicate interface card incorporating at least one said solid state switch.