INGIniousIn some MPLS networks, large LSPs carry smaller LSPs. This improves the scalability of the network by reducing the number of LSPs that need to be handled by the core LSRs.
Consider the network below where the large LSP (shown with a magenta line) carries three small LSPs (shown with dotted red, blue and green lines).
Here is the LFIB of LSR R2
| Label | Nexthop | Operation |
| L7 | RX | POP |
| L8 | RY | POP |
| L2 | RZ | POP |
Here is the LFIB of LSR R3
| Label | Nexthop | Operation |
| L5 | R2 | SWAP(L8) |
| L2 | R2 | SWAP(L7) |
| L7 | R2 | SWAP(L2) |
Here is the LFIB of LSR R1
| Label | Nexthop | Operation |
| L5 | R3 | POP |
Here is the LFIB of LSR R6
| Label | Nexthop | Operation |
| L9 | R1 | SWAP(L5) |
Here is the LFIB of LSR R7
| Label | Nexthop | Operation |
| L9 | R6 | SWAP(L5);PUSH(L9) |
| L8 | R6 | SWAP(L2);PUSH(L9) |
| L7 | R6 | SWAP(L7);PUSH(L9) |
Here is the LFIB of LSR R8
| Label | Nexthop | Operation |
| L11 | R7 | SWAP(L9) |
| L3 | R7 | SWAP(L7) |
| L8 | R7 | SWAP(L8) |