Method in a packet-based communications network including network domains, where at least one domain is an MPLS Multiprotocol Label Switching domain, to establish a virtual leased line, VLL, between a source (SRC) and a destination (DST) ) in different domains in order to achieve packet transfer between the origin and destination, where a bandwidth broker (BB) is associated with each network domain and the network width broker (BB) is adapted to control a hierarchical routing domain, the method includes the following steps: i) generate a request to an entity of a Virtual Leased Line, VLL, which has a predefined Quality of Service, QoS, from a source network (SRC) to a destination network (DST) and apply the request to a Bandwidth Broker (BB) of a domain A, BBA, associated with the home network; ii) BBA establishes the different domains involved to reach the destination network (DST); iii) BBA directly or indirectly passes requests to all Bandwidth Brokers (BB) of the domains involved with respect to a predefined QoS VLL from the entry to the exit of each domain; iv) each bandwidth broker (BB) involved performs admission control in their domain; v) each bandwidth broker (BB) involved returns a result of the admission control to BBA that passes it back to the requesting entity, and if the request was admitted throughout all domains between the origin (SRC) and the destination (DST), a VLL of the predefined QoS is granted.