Enablement of service level agreement negotiation

摘要

The invention relates to a method for enabling Service Level Agreement, SLA, negotiation, in a data center (1) comprising, at a first data center site, overlay and underlay network elements, the overlay network elements including a plurality of virtual machines (2), the underlay network elements including a gateway node (4). The data center (1) is connected to a provider edge node (7) of a carrier network (5) via the gateway node (4) through a User-Network Interface, UNI, (6) between the gateway node (4) and the provider edge node (7). The negotiation of the SLA between the first data center site and the carrier network (5) is controlled by a UNI control function. Egress traffic flows in the overlay network from at least one of the plurality of virtual machines (2) are encapsulated into a virtual network tunnel (8) by a virtual network control function, the virtual network tunnel (8) crossing the gateway node (4) and the UNI (6). The method comprises:- dynamically communicating required Quality of Service, QoS, parameters detained by the virtual network control function to the UNI control function for an egress traffic flow within the virtual network tunnel (8); and- applying the required QoS parameters in the SLA negotiation for the egress traffic flow.