vswitchd: Document behavior of 802.1p priorities with VLAN splinters.

[sliver-openvswitch.git] / vswitchd / vswitch.xml

diff --git a/vswitchd/vswitch.xml b/vswitchd/vswitch.xml
index 5941d22..00cfda6 100644 (file)
--- a/vswitchd/vswitch.xml
+++ b/vswitchd/vswitch.xml
@@ -1921,6 +1921,12 @@
           VLAN splinters increase kernel and userspace memory overhead, so do
           not use them unless they are needed.
         </p>
+
+        <p>
+          VLAN splinters do not support 802.1p priority tags.  Received
+          priorities will appear to be 0, regardless of their actual values,
+          and priorities on transmitted packets will also be cleared to 0.
+        </p>
       </column>
     </group>
 
@@ -2057,8 +2063,19 @@
       supported range of queue numbers depend on <ref column="type"/>.  The
       queue numbers are the same as the <code>queue_id</code> used in
       OpenFlow in <code>struct ofp_action_enqueue</code> and other
-      structures.  Queue 0 is used by OpenFlow output actions that do not
-      specify a specific queue.</p>
+      structures.</p>
+
+      <p>
+        Queue 0 is the ``default queue.''  It is used by OpenFlow output
+        actions when no specific queue has been set.  When no configuration for
+        queue 0 is present, it is automatically configured as if a <ref
+        table="Queue"/> record with empty <ref table="Queue" column="dscp"/>
+        and <ref table="Queue" column="other_config"/> columns had been
+        specified.
+        (Before version 1.6, Open vSwitch would leave queue 0 unconfigured in
+        this case.  With some queuing disciplines, this dropped all packets
+        destined for the default queue.)
+      </p>
     </column>
 
     <group title="Configuration for linux-htb and linux-hfsc">