Example embodiments presented herein are directed towards a target Mobility Management Entity (MME) or a target Serving General Packet Radio Service Support Node (SGSN) network node, and method, for handling a mobility procedure or session procedure within the same operator. The roaming agreement handling may comprise comparing a Quality of Service (QoS) parameter associated with a source system, a maximum QoS associated with a target system and a Packet Data Network Gateway (PGW) or Policy and Changing Rules Function (PCRF) capability. The mobility procedure or session procedure handling may further comprise providing instructions for the roaming procedure based on the comparison.Example embodiments may further comprise a Packet Data Network Gateway (PGW) network node, and method, for adjusting Quality of Service (QoS) during a mobility procedure or session procedure. The adjustment may be based on a received target maximum QoS.