Add ASF measurement lifetime as strategy parameter

Refs: #5332
Change-Id: Iff42ca0870d4263f0ad8757a67b87e52dbfff9f5
diff --git a/docs/manpages/nfd-asf-strategy.rst b/docs/manpages/nfd-asf-strategy.rst
index 45339b8..ff7079a 100644
--- a/docs/manpages/nfd-asf-strategy.rst
+++ b/docs/manpages/nfd-asf-strategy.rst
@@ -24,6 +24,14 @@
     integer). Smaller values will result in higher overhead but faster reaction.
     The default value is 1 minute and the minimum value is 1 second.
 
+.. option:: measurements-lifetime <LIFETIME>
+
+    This optional parameter tells ASF how long to retain NamespaceInfo and FaceInfo
+    measurements if they are not actively updated. If not specified, this value defaults
+    to 5 minutes. This value is specified in (non-negative integer) milliseconds and must
+    be greater than the probing interval, as otherwise there is negligible benefit gained
+    from the additional traffic generated by ASF.
+
 .. option:: max-timeouts <TIMEOUTS>
 
     This optional parameter makes ASF switch to another appropriate face (if available)
@@ -45,8 +53,11 @@
 ``nfdc strategy set prefix /ndn strategy /localhost/nfd/strategy/asf/v=5/max-timeouts~5``
     Set the maximum number of timeouts to 5.
 
-``nfdc strategy set prefix /ndn strategy /localhost/nfd/strategy/asf/v=5/probing-interval~30000/max-timeouts~2``
-    Set the probing interval to 30 seconds and the maximum number of timeouts to 2.
+``nfdc strategy set prefix /ndn strategy /localhost/nfd/strategy/asf/v=5/measurements-lifetime~120000``
+    Set the maximum measurement lifetime to 2 minutes.
+
+``nfdc strategy set prefix /ndn strategy /localhost/nfd/strategy/asf/v=5/probing-interval~30000/max-timeouts~2/measurements-lifetime~120000``
+    Set the probing interval to 30 seconds, the maximum number of timeouts to 2, and the maximum measurement lifetime to 2 minutes.
 
 ``nfdc strategy set prefix /ndn strategy /localhost/nfd/strategy/asf/v=5/retx-suppression-multiplier~2.5/probing-interval~45000``
     Set the retransmission suppression multiplier to 2.5 and the probing interval