Abstract: A method for establishing a data packet exchange communication session that allows the exchange of data packets between an originating client and a destination client in a data network having a client-server arrangement is provided. An originating client transmits communications session request data message to a communications management server via a first temporary signaling communications path. The communications session request data message contains at least a unique network address of a destination client. The communications management server, upon determining that said originating client is residing behind a first network firewall, determining whether said first network firewall will allow exchange of data packets between said originating client and any other client not residing behind said first network firewall.