DOC-2542: Include information on using Pooled MuxIO Connections (#2794)

* DOC-2542: Include information on using Pooled MuxIO Connections

* typo fix

content/sdk/dotnet/client-settings.dita

@@ -594,19 +594,29 @@ var bucket = cluster.OpenBucket("travel-sample");</codeblock></p>
         configure the IOService either through the configuration file (app.config, web.config or
         json settings file) or programmatically using the SDK's ClientConfiguration when
         initializing the Cluster.</p>
-      <p><b>Multiplexing IO Service</b></p>
+      <p><b>Shared-Pooled IO Service w/MUX</b></p>
+      <p>As of v2.5.0, the client uses a Shared-Pooled IO Service for K/V along with Multiplexing
+        (MUX) by default. A shared pool allows multiple threads to use a connection at the same time
+        and each thread is assigned a connection from the pool in a round-robin fashion. This gives
+        the best performance and the benefits of both Multiplexing IO Service and Pooled IO Service.
+        This is the reccomended configuration and is the default from v2.5.0 on - there is no need
+        for additional configuration to use it.</p>
+      <p><b>Multiplexing IO Service (Obsolete)</b></p>
       <p>Multiplexing is when a single TCP connection is used by multiple threads to send and
         receive requests simultaneously. The benefit's are improved throughput with less strain on
         the OS resources and importantly, a reduction on the number of TCP connections between the
         client and the server. The Multiplexing IO Service is the default IO Service if no custom
         configuration is provided.</p>
-      <p><b>Pooled IO Service</b></p>
+      <p><b>Pooled IO Service (SSL only)</b></p>
       <p>Pooled is when the SDK maintains a pool of TCP sockets and each thread uses a single socket
         at one time for Memcached K/V operations (Get, Insert, Remove, etc.). The connection pool
         limit is capped by the MinSize and MaxSize configuration settings; if MaxSize has been
         reached, the SDK would wait for a connection to become available or it would return an
         OperationTimeout response.</p>
-      <p><b>Configuring the IO Service</b></p>
+      <p><b>Configuring the IO Service</b><note>The default IO Service as of v2.6.0 is Shared-Pooled
+          IO Service w/MUX and is the reccomended IO Service to use for non-SSL/TLS. We do not
+          recommend using any of the other IO services or changing the default settings for IO
+          Services as described below.</note></p>
       <p>To configure the IO Service in your configuration file you would set the connectionPool
         element and ioService elements. An example of setting the configuration file to use
         PooledIOService would look like
@@ -655,6 +665,10 @@ ClusterHelper.Initialize(config);</codeblock></p>
             <li>WaitTimeout</li>
           </ul></li>
         <li>MUX has no effect on Views, N1QL or Full Text Search queries</li>
+        <li>Shared-Pooled IO Service w/MUX currently ignores the MinSize and creates the MaxSize of
+          connections configured. This is a known issue/limitation and can be tracked by the
+          following Jira ticket: <xref href="https://issues.couchbase.com/browse/NCBC-1534"
+            format="html" scope="external"/></li>
       </ul>
     </section>
   </body>