A case for dense-mode multicast support in MPLS

In this paper, we propose a new method for dense-mode multicast support in an MPLS domain. Our method uses a unique identifying label for multicast distribution tree. It consumes no label from unicast label space. Label swapping is not required at all, since we use just one label for each multicast tree. This approach results in at least 50% memory savings in LSRs (label switch routers). In our previous method, the tree labels are assigned centrally in the MPLS domain. However, they are assigned in a partially distributed manner by LLAs (local label assigners) in the new scheme. Multicast label ranges are assigned to LLAs proportional to their needs. There is no need for explicit on-demand signaling in this approach. The proposed solution significantly reduces the control messages overhead in comparison with previous work.