ring via the optical switches 462 and 421 thus using a loopback protection switching scheme operations are restored in the ring network 400 for example data may be transmitted from the central office 415 to the central office 435 via the following path co 415 u2192 com link 416 u2192 adm 414 u2192 switch 412 input 412 a u2192 switch 412 output 412 c u2192 switch 461 input 461 a u2192 switch 461 output 461 d u2192 optical fiber 450 3 u2192 switch 463 input 463 c u2192 switch 463 output 463 d u2192 optical fiber 450 2 u2192 switch 462 input 462 c u2192 switch 462 output 462 b u2192 switch 421 input 421 c u2192 switch 421 output 421 a u2192 adm 424 u2192 switch 422 input 422 a u2192 switch 422 output 422 b u2192 optical fiber 440 2 u2192 switch 431 input 431 b u2192 switch 431 output 431 a u2192 adm 434 u2192 com link 436 u2192 co 435 it may be appreciated that the protection ring 450 is connected only to the two nodes 420 and 410 adjacent to each side of the failure the node 430 is completely bypassed by the protection ring 450 referring now to fig1 the ring network 400 is shown with a failed node i e the node 410 depicted by a large.