MPLS TE may be used to divert traffic over an explicit route. The specification of the explicit route is done by enumerating an explicit list of the routers in the path. Given this list, TE trunks can be constructed in a variety of ways. For example, a trunk could be manually configured along the explicit path. This involves configuring each router along the path with state information for forwarding the particular MPLS label.
Alternately, a signaling protocol such RSVP-TE can be used with an EXPLICIT_ROUTE object (ERO) so that the first router in the path can establish the trunk. The ERO is basically a list of router IP addresses.
Constraint-based routing LDP (CR-LDP) is another signaling protocol that can be used ...