Common xN lane connection likes this:
UP DP
Lane0 <----> Lane 0
Lane1 <----> Lane 1
...
LaneN-1 <----> Lane N-1
lane reversal to xN link likes below:
UP DP
Lane0 <----> Lane N-1
Lane1 <----> Lane N-2
...
LaneN-1 <----> Lane 0
原文：https://www.cnblogs.com/lybinger/p/10399970.html