diff --git a/docs/traffic_shaping.xml b/docs/traffic_shaping.xml
index 7e1473384..ef033d7e6 100644
--- a/docs/traffic_shaping.xml
+++ b/docs/traffic_shaping.xml
@@ -379,6 +379,14 @@
           upstream router as you gradually increase the setting.The optimal
           setting is at the point beyond which the <emphasis>ping</emphasis>
           time increases sharply as you increase the setting.</para>
+
+          <note>
+            <para>For fast lines, the actually download speed may be well
+            below what you specify here. If you have this problem, then follow
+            the bandwidth with a ":" and a <firstterm>burst</firstterm> size.
+            The default burst is 10kb, but on my 50mbit line, I specify 200kb.
+            (50mbit:200kb).</para>
+          </note>
         </listitem>
 
         <listitem>