[Freeswitch-users] Adding optional SDP Header in the Invite

Hi, I am looking for a way to add the optional sdp header for the bandwidth in the invite sdp (reference *rfc3890*). I see that the video has the option to modify it with the variables rtp_video_max_bandwidth_in rtp_video_max_bandwidth but for the audio I don't see any options or reference. Regards, Jenish