+------+
                      |      |
              +-------|  P3  |-----+
              | +-----|      |---+ |
            L3| |L4   +------+ L1| |L2     +----+
              | |                | |    +--| P4 |--+
+-----+     +-----+            +-----+  |  +----+  |  +-----+
|  S  |-----| P1  |------------| P2  |--+          +--|  D  |
|     |     |     |            |     |--+          +--|     |
+-----+     +-----+            +-----+  |  +----+  |  +-----+
                                        +--| P5 |--+
                                           +----+
    Key:
        S = Source LSR
        D = Destination LSR
        P1, P2, P3, P4, P5 = Transit LSRs
        L1, L2, L3, L4 = Links