Fix NSX deployment diagram

1. Corrected and redrew the NSX deployment diagram
2. Created another NSX deployment example with VMs on a Compute node

Change-Id: I3f0a7169a3c8dc6dacedad1999b28ee182d25632
backport: juno
Closes-Bug: #1417215

doc/admin-guide-cloud/networking/section_networking_arch.xml

@@ -266,27 +266,38 @@
 </section>
     <section xml:id="NSX_overview">
         <title>VMware NSX integration</title>
-        <para>OpenStack Networking uses the NSX plugin for Networking to
+        <para>OpenStack Networking uses the NSX plugin to
         integrate with an existing VMware vCenter deployment. When installed on
         the network nodes, the NSX plugin enables a NSX controller to centrally
         manage configuration settings and push them to managed network nodes.
         Network nodes are considered managed when they're added as hypervisors
         to the NSX controller.</para>
-        <para>The diagram below depicts an example NSX deployment and
-        illustrates the route inter-VM traffic takes between separate Compute
-        nodes. Note the placement of the VMware NSX plugin and the
+      <para>The diagrams below depict some VMware NSX deployment examples.
+        The first diagram illustrates the traffic flow between VMs on separate
+        Compute nodes, and the second diagram between two VMs on a single
+        Compute node. Note the placement of the VMware NSX plugin and the
         <systemitem class="service">neutron-server</systemitem> service on the
-        network node. The NSX controller features centrally with a green line to
-        the network node to indicate the management relationship:</para>
-        <figure>
-            <title>VMware NSX overview</title>
-            <mediaobject>
-                <imageobject>
-                    <imagedata
-                        fileref="../../common/figures/vmware_nsx.png"
-                        format="PNG" contentwidth="6in"/>
-                </imageobject>
-            </mediaobject>
+        network node. The green arrow indicates the management relationship
+        between the NSX controller and the network node.</para>
+      <figure>
+        <title>VMware NSX deployment example - two Compute nodes</title>
+        <mediaobject>
+          <imageobject>
+            <imagedata
+              fileref="../../common/figures/vmware_nsx_ex1.png"
+              format="PNG" contentwidth="6in"/>
+            </imageobject>
+          </mediaobject>
         </figure>
+        <figure>
+          <title>VMware NSX deployment example - single Compute node</title>
+          <mediaobject>
+            <imageobject>
+              <imagedata
+                fileref="../../common/figures/vmware_nsx_ex2.png"
+                format="PNG" contentwidth="6in"/>
+              </imageobject>
+            </mediaobject>
+          </figure>
     </section>
 </section>