How to get the node role ?

[DaveHu-TVU]

typedef bool (* nmos_connection_rtp_activation_callback)(
NvNmosNodeServer *server,
const char *id,
const char *sdp);

As far as I know, this callback function is triggered when active or deactive or connect is operated on NMOS Server.
Q1: How can I confirm whether it is active/deactive or connect?
Q2: How do I determine if the trigger is sender or receiver?
thanks!

[DaveHu-TVU]

Q3: if I get the video sender deactive callback, the video stream address IP and port was changed from param sdp, even after I re-worked active, I still can't get the original video stream address IP and port, how can I get the original video stream address IP and port after deactive and active ? I tried "nmos_connection_rtp_activate" but it hung.