if I use "fsctl pause" freeswitch should not handle any new call but a INVITE will still be send answered from FreeSWITCH with 407 Proxy Authentication Required. This message go back to the peer. If the peer then send the INVITE with credentials (with authentication) FreeSWITCH sends bacck the 503 "No more sessions" because of the "pause state".

Respond with 503 BEFORE doing the authentication for a INVITE
 - if sess_count > sess_max
 - if profile is not running (PFLAG_RUNNING)
 - core_ready is false

Please find the attached patch.