Case A) Client1(wifi) --> Client2(4G) : Client2 can't get INVITE
Case B) Client2(4G) --> Client1(wifi) : Client1 can get INVITE and talk together
Case C) Cl ...
From my understanding, Brekeke SIP server supports Shared address space from 3.4 so I guess no need to setup something for RFC6598 on Brekeke SIP Server.