                  <-----Primary Path--- (S,G) Join

          [S]---(R1)---(R2)******(R6)-------[R]
                         |        |
                  <---   |        |   |
                     |   |        |   |
                     |   |       (R5) |
                     |   |        |   |
                     |   |        |   |
                     |   |        |   |
                     | (R3)------(R4) |
                     |                |
                     --Secondary Path--