Update on-line manpage to reflect iperf 3.1.5.

docs/invoking.rst

@@ -130,14 +130,22 @@ the executable.
                  packets  without  pausing,  even if that temporarily exceeds the
                  specified bandwidth limit.  Setting the target  bandwidth  to  0
                  will  disable  bandwidth  limits  (particularly  useful  for UDP
-		 tests).  On platforms supporting the  SO_MAX_PACING_RATE  socket
-		 option  (currently  only Linux), fair-queueing socket-level pac-
-		 ing, implemented in the kernel, will be used.   On  other  plat-
-		 forms, iperf3 will implement its own rate control.
+                 tests).  This bandwidth limit is implemented  internally  inside
+                 iperf3,  and  is  available  on all platforms.  Compare with the
+                 --fq-rate flag.
+   
+          --fq-rate n[KM]
+                 Set a rate to be used with fair-queueing based socket-level pac-
+                 ing,  in bits per second.  This pacing (if specified) will be in
+                 addition to any pacing due to iperf3's internal bandwidth pacing
+                 (-b  flag),  and  both can be specified for the same test.  Only
+                 available on platforms supporting the SO_MAX_PACING_RATE  socket
+                 option  (currently only Linux).  The default is no fair-queueing
+                 based pacing.
    
           --no-fq-socket-pacing
-		 disable  the use of fair-queueing based socket-level pacing with
-		 the -b option, and rely on iperf3's internal rate control.
+                 This option is deprecated and will be removed.  It is equivalent
+                 to specifying --fq-rate=0.
    
           -t, --time n
                  time in seconds to transmit for (default 10 secs)
@@ -149,8 +157,11 @@ the executable.
                  number of blocks (packets) to transmit (instead of -t or -n)
    
           -l, --length n[KM]
-		 length of buffer to read or write (default 128 KB for  TCP,  8KB
-		 for UDP)
+                 length  of  buffer to read or write.  For TCP tests, the default
+                 value is 128KB.  In the case of UDP, iperf3 tries to dynamically
+                 determine  a  reasonable  sending size based on the path MTU; if
+                 that cannot be determined it uses 1460 bytes as a sending  size.
+                 For SCTP tests, the default size is 64KB.
    
           --cport port
                  bind  data  streams  to  a specific client port (for TCP and UDP
@@ -236,7 +247,7 @@ the executable.
    
    
    
-   ESnet                              May 2016                          IPERF3(1)
+   ESnet                            January 2017                        IPERF3(1)
 
 The iperf3 manual page will typically be installed in manual
 section 1.