docs/78096: Add info on setting up ATLQ

[Brad Davis]

After going over it again with remko@, here is a new diff.


Brad


--- doc-ori/en_US.ISO8859-1/books/handbook/firewalls/chapter.sgml	Fri Feb 25 13:31:41 2005
+++ doc/en_US.ISO8859-1/books/handbook/firewalls/chapter.sgml	Sat Feb 26 08:54:37 2005
@@ -198,7 +198,7 @@
   </sect1>
 
   <sect1 id="firewalls-pf">
-    <title>The Packet Filter (PF) Firewall</title>
+    <title>The OpenBSD Packet Filter (PF) and ALTQ</title>
 
     <indexterm>
       <primary>firewall</primary>
@@ -211,12 +211,13 @@
       contained <acronym>PF</acronym> as an integrated part of the
       base system was &os; 5.3 in November 2004.
       <acronym>PF</acronym> is a complete, fully featured firewall
-      that contains <acronym>ALTQ</acronym> for bandwidth usage
-      management in a way similar to what DUMMYNET provides in
-      <acronym>IPFW</acronym>.  The OpenBSD project does an
-      outstanding job of maintaining the PF users' guide that it will
-      not be made part of this handbook firewall section as that would
-      just be duplicated effort.</para>
+      that has optional support for <acronym>ALTQ</acronym> (Alternate
+      Queuing).  <acronym>ALTQ</acronym> provides Quality of Service
+      (QoS) bandwidth shaping that allows guaranteeing bandwidth to
+      different services based on filtering rules.  The OpenBSD
+      project does an outstanding job of maintaining the PF User's
+      Guide that it will not be made part of this handbook firewall
+      section as that would just be duplicated effort.</para>
 
     <para>The availability of PF for the various &os; releases and versions is
       summarized below:</para>
@@ -356,6 +357,57 @@
         enable the following option as well:</para>
 
       <programlisting>gateway_enable="YES"            # Enable as Lan gateway</programlisting>
+
+    </sect2>
+    <sect2>
+      <title>Enabling ALTQ</title>
+
+      <para><acronym>ALTQ</acronym> is only available by compiling the
+        options into the &os; Kernel.  <acronym>ALTQ</acronym> is not
+        supported by all of the available network card drivers.  Please
+        see the &man.altq.4; manual page for a list of drivers that are
+        supported in your release of &os;.  The following options will
+        enable <acronym>ALTQ</acronym> and add additional functionality.
+        </para>
+
+      <programlisting>options         ALTQ
+options         ALTQ_CBQ        # Class Bases Queuing (CBQ)
+options         ALTQ_RED        # Random Early Detection (RED)
+options         ALTQ_RIO        # RED In/Out
+options         ALTQ_HFSC       # Hierarchical Packet Scheduler (HFSC)
+options         ALTQ_PRIQ       # Priority Queuing (PRIQ)
+options         ALTQ_NOPCC      # Required for SMP build</programlisting>
+
+      <para><literal>options ALTQ</literal> enables the ALTQ framework.</para>
+
+      <para><literal>options ALTQ_CBQ</literal> enables Class Based
+        Queuing (CBQ).  CBQ allows you to divide a connection's
+        bandwidth into different classes or queues to prioritize
+        traffic based on filter rules.</para>
+
+      <para><literal>options ALTQ_RED</literal> enables Random Early
+        Detection (RED).  RED is used to avoid network congestion.  RED
+        does this by measuring the length of the queue and comparing
+        it to the minimum and maximum thresholds for the queue.  If the
+        queue is over the maximum all new packets will be dropped.  True
+        to its name, RED drops packets from different connections
+        randomly.</para>
+
+      <para><literal>options ALTQ_RIO</literal> enables Random Early
+        Detection In and Out.</para>
+
+      <para><literal>options ALTQ_HFSC</literal> enables the
+        Hierarchical Fair Service Curve Packet Scheduler.  For more
+        information about HFSC see: <ulink
+        url="http://www-2.cs.cmu.edu/~hzhang/HFSC/main.html"></ulink>.
+        </para>
+
+      <para><literal>options ALTQ_PRIQ</literal> enables Priority
+        Queuing (PRIQ).  PRIQ will always pass traffic that is in a
+        higher queue first.</para>
+
+      <para><literal>options ALTQ_NOPCC</literal> enables SMP support
+        for ALTQ.  This option is required on SMP systems.</para>
 
     </sect2>
   </sect1>