Media processing between core and access realms

Hi!

Could you please tell me, is there a possibility to release RTP stream in case if user  and media gateway are located in the different realms (in my case - Core and Access)? I checked BCP "Theory of SIP_Media_relase", but found out no description of my case. There are many examples of media release within a system described, but all of these cases are related to the "left hand" realms, e.g. media flow could be releases only in case of two "Access" realms.

Please check my picture. I'm talking about orange dotted line - RTP stream which goes directly from user A to the Media GW. From L3 point of view - it's possible in my case. User A has a route from his Access realm to the Core.