Re: [TICTOC] [Ntp] WGLC draft-ietf-tictoc-ptp-enterprise-profile

[Wojciech Owczarek <[e-mail]>]

Hi Jeffry,

In practice, the profile-specified value is merely treated as a default (minimum value),  and is configurable on nearly every device I have worked with, bar some OEM modules embedded in other products. Higher message rates are very useful in enterprise environments with high PDV, where Telecom profiles are not the answer. Otherwise agreed, agreed and agreed.

What I know is that there is precedent, namely Brilliant / Juniper GMs which supported mixed uc/mc operation, used to ignore 0x7F for unicast delay response. While in breach of IEEE 1588, it was the sensible thing to do. But I suppose it is a moot point, at least in the light of this profile, just like that product line is dead now.

Anyhow, something to be recorded for the future - "useful information" is the key.

Best regards,
Wojciech

--

Wojciech Owczarek


  Original Message  
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Subject: Re: [TICTOC] [Ntp] WGLC draft-ietf-tictoc-ptp-enterprise-profile

My understanding of the Enterprise profile is that the logMessageInterval field is simply ignored in favor of a profile-specified value. The profile is designed to live alongside non-Enterprise nodes on the same PTP network.

All other profiles are going to put 0x7F in the logMessageInterval field on a unicast reply, so the field can't be used for auto-discovery of parameters with any profile.

I think using 0x7F was a bad idea in the first place, but it's a very clear requirement in 1588-2008. I can't think of any good reason to remove useful information simply because a message was unicast instead of multicast. There's already a flag for that in the header.

Best regards,

Jeffry


---- On Mon, 16 Jul 2018 05:15:31 -0500 Wojciech Owczarek <[e-mail]> wrote ----

All,

I might have asked this question before and I think I know the answer, but just to re-state this:

This being an IEEE 1588 profile, a recommendation to set logMessagePeriod in the enterprise profile delay response header to be the configured master delayReq period, rather than the 0x7F as per the standard for any unicast message, is out of the question?

This would allow the delay message interval to be autodiscovered like it is with multicast delayReq/resp. I have seen this done in the field, just like some slave implementations will try unicast delayReq first, and use multicast if no response received. 0x7F makes sense as an indication that the interval should be negotiated, but not where unicast is used without negotiation. This only adds an extra variable to the otherwise automatic slave configuration.

I have not been keeping up with the protocol revision work, but does anyone know if P1588 was able to tackle this?

Regards,
Wojciech

--

Wojciech Owczarek


  Original Message  
From: [e-mail]
Sent: 16 July 2018 9:12 am
To: [e-mail]; [e-mail]
Cc: [e-mail]; [e-mail]; [e-mail]
Subject: Re: [TICTOC] [Ntp] WGLC draft-ietf-tictoc-ptp-enterprise-profile

Neither do I, thanks a lot, Tal!

 

BR

  Heiko

 

 

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Heiko Gerstung 
Managing Director

MEINBERG® Funkuhren GmbH & Co. KG
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Geschäftsführer/Management: Günter Meinberg, Werner Meinberg, Andre Hartmann, Heiko Gerstung

 

On 04.07.18, 23:34  "TICTOC im Auftrag von Douglas Arnold" <[e-mail] im Auftrag von [e-mail]> wrote:

 

I have no objections to Tal's suggestions.  

 

--- Doug

 

On Tue, Jul 3, 2018 at 3:27 AM, Tal Mizrahi <[e-mail]> wrote:

Hi, 

 

I believe this draft is almost ready for publication, with a couple of comments below.

 

A couple of comments:

- The section "Forbidden PTP Options" should include also unicast discovery and unicast negotiation (mentioned in previous sections).

- In the "Security Considerations" section - I suggest to add a general comment: "General security considerations of time protocols are discussed in [RFC7384]".

 

Thanks,

Tal.

 

On Wed, Jun 27, 2018 at 6:35 AM, Karen O'Donoghue <[e-mail]> wrote:

Folks,

 

This email begins a quick followup WGLC for the following draft:

https://datatracker.ietf.org/doc/draft-ietf-tictoc-ptp-enterprise-profile/

 

This document has been around for a long time, and it has been aligned with the updates planned to IEEE 1588. Please respond on the mailing list with your recommendation on publication of this document along with any final comments that you may have. This WGLC will close on Wednesday 11 July 2018. 

 

Regards,

Karen

 

 

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Doug Arnold

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