[Ntp] NTPv5 KISS code support

[David Venhoek <[e-mail]>]

Hi All,

I have made a pull request with suggested wording for including kiss
code support in ntpv5. The PR can be found
athttps://github.com/mlichvar/draft-ntp-ntpv5/pull/9, the suggested
patch is also included below for completeness. Please do share any
feedback regarding the chosen design, this looked good to me but there
may be better approaches.

Kind regards,
David Venhoek

diff --git a/ntp-ntpv5.xml b/ntp-ntpv5.xml
index 190ab3b..0763f1b 100644
--- a/ntp-ntpv5.xml
+++ b/ntp-ntpv5.xml
@@ -310,6 +310,11 @@
                 In requests a value of 1 is a request for a response in the
                 interleaved mode. In responses a value of 1 indicates the
                 response is in the interleaved mode.</t>
+              <t hangText="0x4: Status message"><vspace/>
+                In requests it is 0. In responses a value of 1 indicates that
+                the response is not a normal time-providing response, and MUST
+                be interpreted according to the clauses in Section <xref
+                format="counter" target="status-message"/></t>
             </list>
           </t>

@@ -354,6 +359,24 @@
         by 4.</t>
     </section>

+    <section title="Status messages" anchor="status-message">
+      <t>Instead of a normal time response, a server may send a
status message by
+        setting the 0x4 flag in the flag field. In such messages, the
timestamps,
+        delay, dispersion, precision and leap indicator header fields SHOULD be
+        sent as 0 by the server, and the client MUST ignore these fields.</t>
+
+      <t>In a status message, the server should populate the first 4
bytes of the
+        Server Cookie header with an NTP kiss of death code. Specifications for
+        such codes MAY change the interpretation of the Era, Poll,
and Timescale
+        header fields.</t>
+
+      <t> Clients MUST support at least the RSTR, DENY and RATE kiss
of death codes.
+        For a RSTR or DENY kiss of death code a client MUST
immediately stop sending
+        further messages to the server. For a RATE kiss of death
code, the client
+        MUST immediately change it message sending rate to send at
most 1 message
+        every interval indicated by the Poll header field.</t>
+    </section>
+
     <section title="Extension Fields">
       <t>The format of NTPv5 extension fields is shown in Figure <xref
           format="counter" target="extension-field"/>.</t>