diff --git a/conf/dialplan/default.xml b/conf/dialplan/default.xml
index dfd0fd0fe6..54544642d5 100644
--- a/conf/dialplan/default.xml
+++ b/conf/dialplan/default.xml
@@ -255,7 +255,10 @@
       </condition>
     </extension>
 
-    <!-- dial via SIP uri -->
+    <!-- 
+	 This extension is used by mod_portaudio so you can pa call sip:someone@example.com
+	 mod_portaudio will pass the entire string to the dialplan for routing.
+    -->
     <extension name="sip_uri">
       <condition field="destination_number" expression="^sip:(.*)$">
 	<action application="bridge" data="sofia/${use_profile}/$1"/>