A method, comprising: - an Optical Network Terminal, ONT, of a Passive Optical Network, PON, inhibiting transmission of non-Extensible Authentication Protocol, EAP, Messages on a controlled port of the ONT, until the ONT receives an EAP-Accept Message from an Optical Line Terminal, OLT,, which is connected to said ONT by a communication link and which serves the ONT, said EAP-Accept Message confirming that an identity of a supplicant seeking to send said non-EAP Messages is authentic, characterized in that - a customer premise equipment, CPE, which is connected to said ONT, at the control of said supplicant, performs sending an EAP-Start Message for reception by the ONT connected to said CPE, - in response to the ONT performing receiving the EAP-Start Message, the ONT performs sending an EAP-Request Identity message, which includes information communicating a request for supplicant authentication information, for reception by the CPE, - in response to the CPE performing receiving the EAP-Request Identity Message, the CPE performs sending an EAP-response Message, which includes the requested supplicant authentication information, - in response to the ONT performing receiving the EAP-Response Message, the ONT performs forwarding the EAP-Response Message for reception by the Optical Line Terminal, OLT,, - the OLT performs receiving the EAP-response message, and performs forwarding the EAP-Response Message for reception by an authentication server that is connected to said OLT, - the authentication server performs receiving the EAP-Response Message, - the authentication server performs determining whether the identity of the supplicant is authentic or not using the supplicant authentication information contained in the EAP-Response Message and information that is maintained on the Authentication Server, - if the identity of the supplicant is determined to be authentic, the authentication server performs sending an EAP-Accept Message to the OLT for reception by the CPE via the OLT and ONT, said OLT forwarding said EAP-Accept Message to the ONT, - in response to receiving the EAP-Accept Message from the OLT at the ONT, the ONT enabling transmission of non-EAP Messages at the controlled port of the ONT, - if the identity of the supplicant is determined to be non-authentic or otherwise non-authenticable, the authentication server performs sending an EAP-Reject Message to the OLT for reception by the CPE via the ONT and the OLT, said OLT forwarding said EAP-Reject Message to the ONT. - an Optical Network Terminal, ONT, of a Passive Optical Network, PON, inhibiting transmission of non-Extensible Authentication Protocol, EAP, Messages on a controlled port of the ONT, until the ONT receives an EAP-Accept Message from an Optical Line Terminal, OLT,, which is connected to said ONT by a communication link and which serves the ONT, said EAP-Accept Message confirming that an identity of a supplicant seeking to send said non-EAP Messages is authentic, - a customer premise equipment, CPE, which is connected to said ONT, at the control of said supplicant, performs sending an EAP-Start Message for reception by the ONT connected to said CPE, - in response to the ONT performing receiving the EAP-Start Message, the ONT performs sending an EAP-Request Identity message, which includes information communicating a request for supplicant authentication information, for reception by the CPE, - in response to the CPE performing receiving the EAP-Request Identity Message, the CPE performs sending an EAP-response Message, which includes the requested supplicant authentication information, - in response to the ONT performing receiving the EAP-Response Message, the ONT performs forwarding the EAP-Response Message for reception by the Optical Line Terminal, OLT,, - the OLT performs receiving the EAP-response message, and performs forwarding the EAP-Response Message for reception by an authentication server that is connected to said OLT, - the authentication server performs receiving the EAP-Response Message, - the authentication server performs determining whether the identity of the supplicant is authentic or not using the supplicant authentication information contained in the EAP-Response Message and information that is maintained on the Authentication Server, - if the identity of the supplicant is determined to be authentic, the authentication server performs sending an EAP-Accept Message to the OLT for reception by the CPE via the OLT and ONT, said OLT forwarding said EAP-Accept Message to the ONT, - in response to receiving the EAP-Accept Message from the OLT at the ONT, the ONT enabling transmission of non-EAP Messages at the controlled port of the ONT, - if the identity of the supplicant is determined to be non-authentic or otherwise non-authenticable, the authentication server performs sending an EAP-Reject Message to the OLT for reception by the CPE via the ONT and the OLT, said OLT forwarding said EAP-Reject Message to the ONT.