i'm use it on freeswitch public ip 47.xx.xx.xx and private ip 172.31.239.38 i'm test it http://kb.asipto.com/freeswitch:kamailio-3.3.x-freeswitch-1.2.x-sbc (freeswitch.bindip= 47.xx.xx.xx ) and 101 to 100 and return 488 There seems to be no problem using it on the intranet and log: 8(21255) NOTICE: {2 26129640 INVITE b1b6df17-7ccd-1239-9990-00163e05779b} acc [acc.c:279]: acc_log_request(): ACC: call missed: timestamp=1601366864;method=INVITE;from_tag=t7jr1405ee9gp;to_tag=dGSi5k2;call_id=b1b6df17-7ccd-1239-9990-00163e05779b;code=488;reason=Not acceptable here;src_user=101;src_domain=172.31.239.38;src_ip=47.xxx.xx.xx;dst_ouser=100;dst_user=100;dst_domain=220.207.94.221

fs log: to 100 ask return INCOMPATIBLE_DESTINATION error

Do you need to modify anything in the public network？ I can't find any information. Please help me? thinks