+-----------+
            | Consumer  |
            +-----------+
                  ^
                  |
            +-----------+             +-----------+
            |    BGP    |             |    BGP    |
            |  Speaker  |<----------->|  Speaker  |  +-----------+
            |    RR1    |             |    RRm    |  | Consumer  |
            +-----------+             +-----------+  +-----------+  
                ^   ^                       ^             ^
                |   |                       |             |
          +-----+   +---------+             +---------+   |
          |                   |                       |   |
    +-----------+       +-----------+             +-----------+
    |    BGP    |       |    BGP    |             |    BGP    |
    |  Speaker  |       |  Speaker  |    . . .    |  Speaker  |
    |    R1     |       |     R2    |             |    Rn     |
    +-----------+       +-----------+             +-----------+
          ^                   ^                         ^
          |                   |                         |
         IGP                 IGP                       IGP