Add DLM port number (#232)

For DOCTEAM-82, part 1
BSC#1179267

xml/ha_storage_basics.xml

@@ -27,13 +27,13 @@
    To avoid single points of failure, redundant communication paths are important
    for &ha; clusters. This is also true for DLM communication. If network bonding
    (Link Aggregation Control Protocol, LACP) cannot be used for any reason, we
-   highly recommend to define a redundant communication channel (a second ring)
+   highly recommend defining a redundant communication channel (a second ring)
    in &corosync;. For details, see <xref
    linkend="pro-ha-installation-setup-channel2"/>.
   </para>
   <para>
-   Depending on the configuration in &corosync.conf;, DLM then decides
-   whether to use the TCP or SCTP protocol for its communication:
+   DLM communicates through port 21064 using either the TCP or SCTP protocol,
+   depending on the configuration in &corosync.conf;:
   </para>
  <itemizedlist>
   <listitem>