A method of operation within a user home network utilizing a session-based protocol, the method comprising: at an intermediary entity of the user home network; receiving a capabilities request message transmitted from a first entity, the first entity and the intermediary entity being distinct, the capabilities request message comprising a first modification of a request message associated with the session-based protocol and addressed to a second entity; wherein the method is characterised by: determining whether the capabilities request message includes an information element appended to the request message associated with the session-based protocol; when the capabilities request message does not include the IE, forwarding the capabilities request message to the second entity; when the capabilities request message includes the IE: collecting capabilities of one of more devices associated with the second entity in accordance with one or more values included in the EE, and sending to the first entity a capabilities response message comprising a second modification of a response message associated with the session-based protocol, wherein the capabilities response message includes a set of capabilities of the one or more devices associated with the second entity and a unique identifier for each of the multiple devices to identify which capabilities of the set of capabilities belong to each device. at an intermediary entity of the user home network; receiving a capabilities request message transmitted from a first entity, the first entity and the intermediary entity being distinct, the capabilities request message comprising a first modification of a request message associated with the session-based protocol and addressed to a second entity; wherein the method is characterised by: determining whether the capabilities request message includes an information element appended to the request message associated with the session-based protocol; when the capabilities request message does not include the IE, forwarding the capabilities request message to the second entity; determining whether the capabilities request message includes an information element appended to the request message associated with the session-based protocol; when the capabilities request message does not include the IE, forwarding the capabilities request message to the second entity; when the capabilities request message includes the IE: collecting capabilities of one of more devices associated with the second entity in accordance with one or more values included in the EE, and sending to the first entity a capabilities response message comprising a second modification of a response message associated with the session-based protocol, wherein the capabilities response message includes a set of capabilities of the one or more devices associated with the second entity and a unique identifier for each of the multiple devices to identify which capabilities of the set of capabilities belong to each device. collecting capabilities of one of more devices associated with the second entity in accordance with one or more values included in the EE, and sending to the first entity a capabilities response message comprising a second modification of a response message associated with the session-based protocol, wherein the capabilities response message includes a set of capabilities of the one or more devices associated with the second entity and a unique identifier for each of the multiple devices to identify which capabilities of the set of capabilities belong to each device.