oping: Add alias for the "Voice Admit" DSCP.

[liboping.git] / src / mans / oping.pod

diff --git a/src/mans/oping.pod b/src/mans/oping.pod
index 066451457fdbc934cdd64020429f4fcd0a154769..dba318c14dec50e0446803652d8e586062d1d7f1 100644 (file)
--- a/src/mans/oping.pod
+++ b/src/mans/oping.pod
@@ -71,8 +71,111 @@ returned by L<geteuid(2)>) differ, the only argument allowed for this option is
 "-" (i.E<nbsp>e. standard input). This is meant to avoid security issues when
 I<oping> is installed with the SUID-bit.
 
+=item B<-Q> I<qos>
+
+Specify the I<Quality of Service> (QoS) for outgoing packets. This is a
+somewhat tricky option, since the meaning of the bits in the IPv4 header has
+been revised several times.
+
+The currently recommended method is I<Differentiated Services> which is used in
+IPv6 headers as well. There are shortcuts for 13E<nbsp>predefined
+I<per-hop behaviors> (PHBs):
+
+=over 4
+
+=item B<be>
+
+Selects the I<Best Effort> behavior. This is the default behavior.
+
+=item B<ef>
+
+Selects the I<Expedited Forwarding> (EF) per-hop behavior, as defined in
+I<RFCE<nbsp>3246>. This PHB is characterised by low delay, low loss and low
+jitter, i.e. high priority traffic.
+
+=item B<va>
+
+Selects the I<Voice Admitted> (VA) per-hop behavior, as defined in
+I<RFCE<nbsp>5865>. This traffic class is meant for I<Voice over IP> (VoIP)
+traffic which uses I<Call Admission Control> (CAC) for reserving network
+capacity.
+
+=item  B<af>I<c>I<p>
+
+Selects one of 12E<nbsp>differentiated services code points (DSCPs), which are
+organized in four I<classes> with three I<priorities> each. Therefore, I<c>
+must be a number betweenE<nbsp>1 throughE<nbsp>4 and I<p> must be a number
+betweenE<nbsp>1 throughE<nbsp>3, for example "af13", "af22" and "af41". In each
+class, the lower priority number takes precedence over the higher priority
+number.
+
+=item B<cs>I<n>
+
+Selects one of the eight I<Class Selector> PHBs. I<n> is a number
+betweenE<nbsp>0 throughE<nbsp>7. The class selectors have been defined to be
+compatible to the I<Precedence> field in the IPv4 header as defined in
+I<RFCE<nbsp>791>. Please note that "cs0" is synonymous to "be".
+
+=back
+
+The old definition of the same bits in the IPv4 header was as I<Type of
+Service> (ToS) field, specified in I<RFCE<nbsp>1349>. It defined four possible
+values which have appropriate aliases. Please note that this use of the bits is
+B<deprecated> and the meaning is limited to IPv4!
+
+=over 4
+
+=item B<lowdelay>
+
+Minimize delay
+
+=item B<throughput>
+
+Maximize throughput
+
+=item B<reliability>
+
+Maximize reliability
+
+=item B<mincost>
+
+Minimize monetary cost
+
 =back
 
+Alternatively, you can also specify the byte manually. You can use either a
+decimal number (0-255), a hexadecimal number (0x00-0xff) or an octal number
+(00-0377) using the usual "0x" and "0" prefixes for hexadecimal and octal
+respectively.
+
+The printed lines will contain information about the QoS field of received
+packets if either a non-standard QoS setting was used on outgoing packets or if
+the QoS byte of incoming packets is not zero. In other words, the QoS
+information is omitted if both, the outgoing and the incoming QoS bytes are
+zero. The received byte is always interpreted as
+I<Differentiated Services Code Point> (DSCP) and
+I<Explicit Congestion Notification> (ECN), even if the deprecated
+I<Type of Service> (ToS) aliases were used to specify the bits of outgoing
+packets.
+
+=back
+
+=head1 COLORS
+
+If supported by the terminal, I<noping> will highlight the round-trip times
+(RTT) using the colors green, yellow and red. Green signals RTTs that are in
+the "expected" range, yellow marks moderately unusual times and times that
+differ a lot from the expected value are printed in red.
+
+The information used to categorize round-trip times is the I<average>
+round-trip time and the I<standard deviation>. RTTs that differ from the
+average by less than the standard deviation are considered to be "normal" and
+are printed in green. Times that differ from the average more than the standard
+deviation but less than twice the standard deviation are considered "moderately
+unusual" and are printed in yellow. Times differing more than twice the
+standard deviation from the average are considered to be "unusual" and are
+printed in red.
+
 =head1 SEE ALSO
 
 L<ping(8)>, L<http://www.fping.com/>, L<liboping(3)>