Re: [Ntp] NTPv5 draft

[Dieter Sibold <[e-mail]>]

Hi Miroslav

Many thanks for your NTPv5 proposal.

With my working group chair’s hat off!

I have following comments:


1. Security

The protocol as proposed is missing a security approach. There are no 
mechanisms described to provide authentication, integrity protection and 
maybe encryption. I very much agree with Jame’s proposed draft that a 
new version of NTP must provide these mechanisms by default.  Sure, you 
can add NTS to protect the NTPv5 packets. But in this case protection is 
always an optional add-on whereas it needs to be an inherent part of the 
basic protocol. To achieve this the NTS approach certainly can be 
transferred to the basic v5 protocol and packet format.




2. Interleave and 2-Step

I agree with Doug to decide with approach to provide with NTPv5. 
Providing both 2-Step and Interleave may increase complexity 
unnecessarily. Personally, I find that the 2-step approach with the 
follow-up message is more concise. And since the first message only need 
to be very small (it just needs to contain the information to ensure 
correlation with the follow up) the waste of network bandwidth is very 
small.



3. Traceability

It would make sense that the v5-packets optionally provide information 
about the uncertainty of the timestamps taken. These formally for 
establishing traceability. Additionally, in order to maintain 
traceability during the time period in which leap smearing is applied 
the client needs to obtain the necessary information to calculate the 
offset between UTC and smeared time. This also is mandatory to maintain 
traceability.


Dieter









On 11 Nov 2020, at 17:19, Miroslav Lichvar wrote:

> As promised on the previous meetings, I wrote an NTPv5 draft. It's
> based on the proposal I sent to this list few months ago, with few
> improvements like timestamp fields seperated from cookies, etc. It
> still needs a lot of work to be able to stand on its own, but I think
> it should be good enough for people here to understand how it is
> intended to work.
>
> It's too late to submit it for the upcoming meeting. Here is a link to
> a txt version if anyone would like to read it and discuss it here:
>
> https://gist.github.com/mlichvar/2bee94a706d60da9ca88d712afef083e
>
> -- 
> Miroslav Lichvar
>
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