Hi , i want to oblige an extension example 400 to not be registered . so soft --------------------register--------------------------------> server soft <-----------------unauthorized (first 401)----------------server soft ---------------------register (with authorization header computed with the nonce of the 401)----------------------------------------------------->server soft <--------------------unauthorized (with stale ==False) ---->server i did this in dialplan/default.xml: <extension name="fail register"> <condition field="caller_id_number" expression="^400$"> <action application="respond" data="401"/> <action application="hangup"/> </condition> </extension> i have only one unauthorized then i have ok ,but how can i do to have this result . thank you with best regards , amani