Hi all, I have configure freeswitch as SBC server with one asterisk server. I am getting nat issue when make call from FS to FS. my case as: client --- FS ----- Asterisk server ----- FS -----client. my configure in public.xml like: <extension name="asteirsk"> <condition field="destination_number" expression="(\d+)$" require-nested="true"> <condition field="network_addr" expression="^192\.168\.1\.123$" break="never"> <action application="set" data="hangup_after_bridge=true"/> <action application="export" data="sip_h_X-ROUTE=LOOKUP"/> <action application="set" data="bypass_media=true"/> <action application="bridge" data="user/${destination_number}@${domain_name}"/> <anti-action application="set" data="hangup_after_bridge=true"/> <anti-action application="export" data="sip_h_X-ROUTE=LOOKUP"/> <anti-action application="set" data="bypass_media=true"/> <anti-action application="bridge" data="sofia/internal/${destination_number}@192.168.1.123"/> </condition> </condition> </extension> Call is process ok, But I see that when I answer call in destination, asterisk server alway send 200OK to my FS, FS return ACk, but asterisk resend 200OK. if any one can help, thank all alot. I am getting this stage to long and cant find any solution here. Thanks, ThanhTruong