A method of and an application server and user equipment for providing at least one of chat and Voice over Internet Protocol, chat/VoIP, services to the mobile user equipment in a mobile telecommunications network. The mobile user equipment comprises a chat/VoIP client for accessing a chat/VoIP service application interfacing the mobile telecommunications network. The chat/VoIP service application interfaces a plurality of proprietary chat/VoIP clients for accessing a plurality of proprietary chat/VoIP communication environments operated by a plurality of chat/VoIP service providers, for providing chat/VoIP services to the chat/VoIP client of the mobile user equipment. The chat/VoIP client and the chat/VoIP service application may be arranged such that privileged use of the mobile telecommunications network is enabled, providing a session between the user equipment and a communication environment with a predetermined or agreed Quality of Service.