diff --git a/asterisk/conf/mobile/extensions.conf b/asterisk/conf/mobile/extensions.conf
new file mode 100644
index 0000000..7ce4d61
--- /dev/null
+++ b/asterisk/conf/mobile/extensions.conf
@@ -0,0 +1,14 @@
+; /etc/asterisk/extensions.conf
+
+; Remember, context names for each SIP account are specified in pjsip_wizard.conf.
+;
+; First, some safeguards against abuse of the built-in contexts.
+[default]
+exten=>s,1,Verbose(1, "INFO ${CALLERID(num)} was passed to default.")
+same=>n,Hangup(3)
+
+[presence]
+exten=>_X.,hint,PJSIP/${EXTEN}
+
+[from-ext]
+exten=>123,1,Hangup(3)