A method of providing at least one of chat and Voice over Internet Protocol, chat/VoIP, services to a mobile User Equipment, UE, in a mobile telecommunications network , said mobile UE comprises a UE chat/VoIP client for accessing a chat/VoIP communication environment , said method comprises the steps of: - connecting a chat/VoIP service application and said UE chat/VoIP client by said mobile telecommunications network , and - connecting said chat/VoIP service application and at least one of a plurality of application server chat/VoIP clients for accessing a plurality of chat/VoIP communication environments operated by a plurality of chat/VoIP service providers, for providing chat/VoIP services to said UE chat/VoIP client by each accessed chat/VoIP communication environment , characterized by - acting as a chat/VoIP client, by said chat/VoIP service application , towards a connected chat/VoIP communication environment by at least one of said plurality of application server chat/VoIP clients , said chat/VoIP communication environment being proprietary or standardized, and - acting as a chat/VoIP communication environment, by said chat/VoIP service application , towards said UE chat/VoIP client , and wherein said chat/VoIP service application and said plurality of application server chat/VoIP clients are comprised by an application server comprised by said mobile telecommunication network, wherein said acting as a chat/VoIP client and acting as a chat/VoIP communication environment comprise setting up and accepting chat/VoIP communication sessions (70; 71, 72, 73) providing privileged use of the mobile telecommunications network , in particular providing an agreed Quality of Service, QoS, further wherein said application server chat/VoIP clients provide protocol conversion between a proprietary or standardized chat/VoIP communication environment and said chat/VoIP communication environment provided by said chat/VoIP service application acting towards said UE chat/VoIP client , wherein said protocol conversion comprises coordinating and mapping of chat/VoIP services, features and functions of a chat/VoIP communication environment to and from a UE chat/VoIP client . - connecting a chat/VoIP service application and said UE chat/VoIP client by said mobile telecommunications network , and - connecting said chat/VoIP service application and at least one of a plurality of application server chat/VoIP clients for accessing a plurality of chat/VoIP communication environments operated by a plurality of chat/VoIP service providers, for providing chat/VoIP services to said UE chat/VoIP client by each accessed chat/VoIP communication environment , characterized by - acting as a chat/VoIP client, by said chat/VoIP service application , towards a connected chat/VoIP communication environment by at least one of said plurality of application server chat/VoIP clients , said chat/VoIP communication environment being proprietary or standardized, and - acting as a chat/VoIP communication environment, by said chat/VoIP service application , towards said UE chat/VoIP client , and wherein said chat/VoIP service application and said plurality of application server chat/VoIP clients are comprised by an application server comprised by said mobile telecommunication network, <EOS>