A method and Domain Name System (DNS) server for establishing a communication session in an Internet Protocol (IP)-based communication network. The DNS server receives a query containing a DNS name of a destination terminal as a search key, and determines whether an IP address for the DNS name is registered with the DNS server. If so, the DNS server returns the registered IP address to the sender of the query. If not, the DNS server sends a wake-up message to the destination terminal which, in response, establishes an IP data session with the communication network. The DNS server then receives an IP address for the destination terminal from an access server or from a Dynamic Host Control Protocol (DHCP) server, and returns the received IP address to the sender of the query.