3.1.5.29.2 User agent behavior for a=x-devicecaps attribute

A user agent SHOULD<56> indicate in any SDP message it sends what device capabilities it currently supports using the a=x-devicecaps attribute.

However, an MCU SHOULD NOT include any x-devicecaps attributes in SDP messages it sends, and SHOULD ignore the x-devicecaps attribute in any SDP messages it receives.

If the device-type is not recognized by the receiving user agent, the device-capability MUST be ignored.

If the device-type is recognized, the receiving user agent SHOULD indicate the peer’s device capability within its user interface in some appropriate fashion. For example, for the video device-capability, the user agent can display a web camera icon, to suggest that a video modality can be engaged with the peer.