Wrote a little intro.

git-svn-id: https://svn.php.net/repository/phpdoc/en/trunk@308877 c90b9560-bf6c-de11-be94-00142212c4b1

reference/snmp/book.xml

@@ -2,7 +2,7 @@
 <!-- $Revision$ -->
 <!-- Purpose: remote.other -->
 <!-- Membership: bundled, external -->
- 
+
 <book xml:id="book.snmp" xmlns="http://docbook.org/ns/docbook" xmlns:xlink="http://www.w3.org/1999/xlink">
  <title>SNMP</title>
  
@@ -10,7 +10,16 @@
  <preface xml:id="intro.snmp">
   &reftitle.intro;
   <para>
-   SNMP Functions.
+   The SNMP extension provides a very simple and easily usable toolset for
+   managing remote devices via the Simple Network Managment Protocol.
+  </para>
+  <para>
+   As it is a wrapper around the underlying Net-SNMP (or UCD-SNMP on older systems)
+   library, all basic concepts are the same and the PHP functions change their
+   behaviour depending on the Net-SNMP configuration files and environment variables.
+  </para>
+  <para>
+   More information about Net-SNMP can be found on http://www.net-snmp.org/.
   </para>
  </preface>
  <!-- }}} -->
@@ -18,7 +27,7 @@
  &reference.snmp.setup;
  &reference.snmp.constants;
  &reference.snmp.reference;
-
+ 
 </book>
 
 <!-- Keep this comment at the end of the file