This might sound crazy and unholy but is it possible to have MPLS prefixes like IP prefixes. MPLS label like an IP address is just a number (20 vs 32bits). There is no reason we can't have a MPLS prefix and mask similar to IP. The reason for aggregation can be the same as IP (save router memory). The lookups will be a little slower (longest prefix matching), but that problem has already been mostly solved by fast algorithms. Has this been done/ Why don't people do it?