A packet transmission method is provided when there occurs a double fault
in working paths of a 1:N configuration and when packets thereon are to
be bypassed from the working paths to a recovery path, the packet can be
transferred to the recovery path while retaining packet priority classes
or VPNs on the recovery path. If faults occur in both a first line on
which is set a first label-switched path and a second line on which is
set a second label-switched path, packets which should flow respectively
through the first and second label-switched paths are bypassed to the
recovery path. At this time, different labels are affixed to the packets
such that the thus-labeled packets are transferred to the recovery path.