Add OsmoSGSN control interface description
diff --git a/doc/manuals/osmosgsn-usermanual.adoc b/doc/manuals/osmosgsn-usermanual.adoc
index d532a31..12a7b87 100644
--- a/doc/manuals/osmosgsn-usermanual.adoc
+++ b/doc/manuals/osmosgsn-usermanual.adoc
@@ -9,6 +9,8 @@
 
 include::chapters/running.adoc[]
 
+include::chapters/control.adoc[]
+
 include::../common/chapters/vty.adoc[]
 
 include::../common/chapters/logging.adoc[]