A method of retrieving an address of a previously unknown resource based on the location of the invoking user by consulting a known resource is provided. A user terminal, while roaming, may select an optimal gateway for providing multimedia communications to the terminal by first sending a service request to the terminal's home gateway. In response, the home gateway determines the optimal gateway for use by the user based on the location of the invoking user. The address of the optimal gateway, as determined by the home gateway, is sent to the invoking user terminal, wherein the user sends a service request to the optimal gateway.