Nokia Siemens Networks CTTC The paths chosen by Generalized MPLS (GMPLS) Traffic Engineering (TE) Label Switched Paths (LSPs) can be constrained using the Explicit Route (ERO) object and related sub-objects. Standard ERO sub-objects can specify the Autonomous System (AS), LSR Node Ids, Numbered or unnumbered TE links, downstream and upstream labels, and PCE path keys thus restricting which resources are to be used by a TE-LSP. The Explicit Label Control (ELC) in the explicit route object (ERO) allows both terminating an LSP on a particular outgoing port and label of an egress node, as well as restricting which label to use on any hop along the path determined by the route. However, currently, its not allowed to specify more than 2 labels (downstream and upstream label), and it is not possible to specify, for a given section or segment of a TE-LSP path, a set of labels to restrict which label to be allocated from a Set of candidate labels. This memo provides extensions to the RSVP-TE and PCEP protocols to support Label Sets in the form of ERO sub-objects, being applicable to ERO and ERO-like (IRO, RRO, XRO) sub-objects, extending the ELC concept to a set of candidate labels.