The label distribution protocol specified in [1] describes a mechanism whereby one label switched router informs another of the meaning of labels used to forward traffic between and through them. This draft proposes a label aggregation technique to reduce the number of labels that need to be exchanged between two LSRs running LDP. This includes a method of signalling that LSRs are capable of label aggregation, determining when a label request can be aggregated on to an existing LSP and a method of signalling to upstream LSRs that the resulting label mapping is an aggregate.