3.1.5.18.5 a=applicationsharing-contentflow attribute

The a=x-applicationsharing-contentflow attribute is used to negotiate the RDP direction of flow of media stream. The attribute is optional; its absence indicating that RDP media stream is allowed to flow in all directions. This attribute SHOULD<31> be included.

applicationsharing-contentflow has the following format in ABNF notation, as described in [RFC5234]:

    contentflow-attribute = “a=x-application-contentflow:” (“sendonly” | “recvonly” | “inactive” ) CRLF

The value “sendonly” indicates that the party making the SDP offer wants to negotiate the direction of flow of RDP media stream as from the offerer to the party receiving the SDP offer. Similarly, the value “recvonly” indicates that the offerer wants to negotiate the direction of flow of media stream from the party receiving the SDP offer to the party negotiating it. The value “inactive” indicates that the media stream is paused and not to flow in either direction. 

The following table lists the possible values of the attribute in the SDP offer and the corresponding SDP answer.

Offer	Answer
a=x-applicationsharing-contentflow:sendonly	a=x-applicationsharing-contentflow:recvonly or a=x-applicationsharing-contentflow:inactive
a=x-applicationsharing-contentflow:recvonly	a=x-applicationsharing-contentflow:sendonly or a=x-applicationsharing-contentflow:inactive
a=x-applicationsharing-contentflow:inactive	a=x-applicationsharing-contentflow:inactive