A traffic handling decision module for use in a network entity of a mobile communication system, wherein the traffic handling decision module is provided within an instance implementing, on the network entity, a mobile network function according to a current software version, wherein the traffic handling decision module comprises: a receiving sub-module configured to receive control plane traffic, the control plane traffic comprising requests to the mobile network function; characterized by a decision sub-module configured to decide, for each received request, whether a respective request is to be processed by an instance implementing the mobile network function according to the current software version or an instance implementing the mobile network function according to an upgraded software version; a routing sub-module configured to route each request to either an instance implementing the mobile network function according to the current software version or an instance implementing the mobile network function according to the upgraded software version, depending on the decision of the decision sub-module; wherein the decision sub-module is configured to perform its decision based on one or more policies set by a management entity of the mobile communication network; wherein the one or more policies include a policy according to which requests of the control plane traffic related to a bearer or session established prior to activation of the policy are to be routed to an instance implementing the mobile network function according to the current software version; wherein the one or more policies include a policy according to which requests of the control plane traffic related to a new bearer or session to be established after activation of the policy are to be routed to an instance implementing the mobile network function according to the upgraded software version. a receiving sub-module configured to receive control plane traffic, the control plane traffic comprising requests to the mobile network function; characterized by a decision sub-module configured to decide, for each received request, whether a respective request is to be processed by an instance implementing the mobile network function according to the current software version or an instance implementing the mobile network function according to an upgraded software version; a routing sub-module configured to route each request to either an instance implementing the mobile network function according to the current software version or an instance implementing the mobile network function according to the upgraded software version, depending on the decision of the decision sub-module; wherein the decision sub-module is configured to perform its decision based on one or more policies set by a management entity of the mobile communication network; wherein the one or more policies include a policy according to which requests of the control plane traffic related to a bearer or session established prior to activation of the policy are to be routed to an instance implementing the mobile network function according to the current software version; wherein the one or more policies include a policy according to which requests of the control plane traffic related to a new bearer or session to be established after activation of the policy are to be routed to an instance implementing the mobile network function according to the upgraded software version.