diff --git a/modules/rtpengine/doc/rtpengine_admin.xml b/modules/rtpengine/doc/rtpengine_admin.xml
index 2c8bab5f1b5..6be5386f3e6 100644
--- a/modules/rtpengine/doc/rtpengine_admin.xml
+++ b/modules/rtpengine/doc/rtpengine_admin.xml
@@ -265,9 +265,13 @@ modparam("rtpengine", "setid_avp", "$avp(setid)")
Forces all control messages between the &sip; proxy and
the &rtp; proxy to be sent from the specified local
- interface. Only IPv4 addresses are supported so far. If
+ interface. Both IPv4 and IPv6 addresses are supported. If
not specified, the default interface selected by the
operating system will be used.
+ Note: when rtpengine_sock is a IPv6 link-local address,
+ one _must_ set this parameter in order to successfully connect to RTP engine.
+ This is necessarely because OS needs additional scope_id hint to communicate
+ over IPv6 link locals. The scope_id is resolved based on the given IPv6.
There is no default value.
@@ -277,6 +281,7 @@ modparam("rtpengine", "setid_avp", "$avp(setid)")
...
modparam("rtpengine", "force_send_interface", "10.3.7.123")
+modparam("rtpengine", "force_send_interface", "2001:8d8:1ff:10c0:9a90:96ff:fea8:fd99")
...