+---+       +-----+       +-----+      +-----+         +-----+
|   |I1     |     |       |     |      |     |       I2|     |
|   |o------|     |-------[(3R) ]------|     |--------o|     |
|   |       |     |       |     |      |     |         |     |
+---+       +-----+       +-----+      +-----+         +-----+
    (X  LSC)     (LSC  LSC)    (LSC  LSC)     (LSC  X)
     <------->   <------->       <----->     <------->
     <-----------------------><---------------------->
      Transparent Segment         Transparent Segment
    <------------------------------------------------->
                           LSC LSP