Hi, Freeswitch Team There is problem for to modify the outbound sip header. As the freeswitch wiki says, it can modify/add custom sip header via below method: <action application="set" data="sip_h_X-Charge=1"/> <action application="set" data="sip_rh_X-Reason=Destination Number Not in Footprint"/> <action application="set" data="sip_bye_h_X-Accounting=Some Accounting Data"/> Now, I add the red lines in dialplan/default.xml. But only the custom header prefixed with "sip_h_" can be shown in the SIP INVITE message. Other custom headers prefixed with "sip_bye_h" and "sip_ph"... not found in the related messages(BYE, 183). Could you kindly give comments about this case? <context name="from-pstn-to-sip"> <extension name="to-sip"> <!-- handle the case where there might not be destination number at all --> <condition field="destination_number" expression="^(.{1,})$" break="never"> <action application="set" data="destnumber=$1"/> <anti-action application="set" data="destnumber=unknown"/> </condition> <!-- Dial to the gateway user (it may ring multiple registrations, first answer wins) --> <condition field="destination_number" expression="^(.*)$"> <action application="set" data="hangup_after_bridge=yes" /> <action application="set" data="tone_detect_hits=1" /> <action application="export" data="fax_enable_t38_request=true" /> <action application="export" data="fax_enable_t38=true" /> <action application="tone_detect" data="faxdisable 1100 r +5000 disable_ec 1"/> <action application="export" data="execute_on_answer=tone_detect fax_disable_ec 2100 r +5000 t38_gateway 'self nocng'" /> <action application="set" data="sip_contact_user_replacement=${destnumber}"/> <action application="set" data="hangup_after_bridge=yes"/> <!-- Uncomment this line to switch to SIP INFO when remote SDP does not support RFC-2833 --> <action application="export" data="sip_info_when_no_2833=false" /> <action application="set" data="sip_h_X-Charge=1"/> <action application="set" data="sip_rh_X-Reason=Destination Number Not in Footprint"/> <action application="set" data="sip_bye_h_X-Accounting=Some Accounting Data"/> <!-- Uncomment the line below to call directly to a SIP endpoint --> <!-- <action application="bridge" data="sofia/internal/${destnumber}@${sip_remote_ip}:${sip_remote_port}"/> --> <!-- <action application="bridge" data="${sofia_contact($${gwuser}@$${domain})}"/> --> <action application="bridge" data="sofia/external/sip:${destination_number}@172.20.2.17:5062"/> <action application="hangup" data="${originate_disposition}"/> </condition> </extension> Thanks Windy