A method for avoiding loops from forming when setting up label switched
paths is provided. The method uses a Label Splicing Message is followed by
an Acknowledgment message to determine if loops are formed in the process
of joining a new node or subtree to a multicast MPLS tree. By verifying
that the path towards the root of the MPLS tree is loop-free during the
construction of the tree, this method complements the loop detection
mechanism provided by the label switched protocol (LDP).
