Re: [Detnet] draft-geng-detnet-requirements-bounded-latency-02 revised for comments

[Stewart Bryant <[e-mail]>]

If the ITU have specifications that cover our needs we should reference 
them. From an IETF perspective there is no procedural issue with 
referencing ITU specifications.

Characterizing oscillators is a complex and difficult task, and the ITU 
has a lot more expertise in that than IETF does, so we should use there 
work if possible.

- Stewart


On 27/06/2019 13:01, qiangli (D) wrote:
> Hi Peter,
> 
> Referencing ITU standards is acceptable IMHO. Let's see others’ opinion.
> 
> Best regards,
> 
> Cristina QIANG
> 
> *From:*[e-mail] [mailto:[e-mail]]
> *Sent:* Thursday, June 27, 2019 6:59 PM
> *To:* qiangli (D) <[e-mail]>; [e-mail]
> *Cc:* [e-mail]; [e-mail]; 
> [e-mail]
> *Subject:* RE: draft-geng-detnet-requirements-bounded-latency-02 revised 
> for comments
> 
> Cristina,
> 
> Personally I think it would be useful to reference such ITU standards if 
> it does not cause IETF procedure issues.
> 
> Best Regardsyyo
> 
> Peter.
> 
> *From:*qiangli (D) <[e-mail] <mailto:[e-mail]>>
> *Sent:* 27 June 2019 10:26
> *To:* Willis,PJ,Peter,TUD1 R <[e-mail] 
> <mailto:[e-mail]>>; [e-mail] 
> <mailto:[e-mail]>
> *Cc:* [e-mail] <mailto:[e-mail]>; 
> [e-mail] 
> <mailto:[e-mail]>; [e-mail] 
> <mailto:[e-mail]>
> *Subject:* RE: draft-geng-detnet-requirements-bounded-latency-02 revised 
> for comments
> 
> Hi Peter,
> 
> The relationship between clock jitter& wander and packet jitter is very 
> complicated, varies a lot depend on different mechanisms. I know there 
> are some time synch stands such as G.8273.2, G.8262. Is it helpful to 
> reference this stands?
> 
> Best regards,
> 
> Cristina QIANG
> 
> *From:*[e-mail] 
> <mailto:[e-mail]>[mailto:[e-mail]]
> *Sent:* Wednesday, June 26, 2019 6:20 PM
> *To:* [e-mail] <mailto:[e-mail]>; 
> qiangli (D) <[e-mail] <mailto:[e-mail]>>
> *Cc:* [e-mail] <mailto:[e-mail]>; 
> [e-mail] 
> <mailto:[e-mail]>; [e-mail] 
> <mailto:[e-mail]>
> *Subject:* RE: draft-geng-detnet-requirements-bounded-latency-02 revised 
> for comments
> 
> Colleagues,
> 
>  From a network operator’s point of view I do not want the extra cost of 
> highly accurate clocks in routers so prefer Detnet to work with the 
> current clocks I have in routers. For an exact specification we would 
> have to list the clock specifications in the typical routers that 
> network operators use (it’s not information I have at my fingertips).
> 
> I also put this requirement in to test what assumptions we are making 
> about clock jitter & wander, and to check those assumptions are 
> reasonable in practice. If there is a correlation between clock jitter & 
> wander and packet jitter then that needs to be understood and stated.
> 
> Best Regards,
> 
> Peter.
> 
> *From:*Janos Farkas <[e-mail] 
> <mailto:[e-mail]>>
> *Sent:* 26 June 2019 10:37
> *To:* qiangli (D) <[e-mail] <mailto:[e-mail]>>
> *Cc:* [e-mail] <mailto:[e-mail]>; 
> [e-mail] 
> <mailto:[e-mail]>; Willis,PJ,Peter,TUD1 R 
> <[e-mail] <mailto:[e-mail]>>; Liang GENG 
> <[e-mail] <mailto:[e-mail]>>
> *Subject:* RE: draft-geng-detnet-requirements-bounded-latency-02 revised 
> for comments
> 
> Hi Cristina,
> 
> Thank you for your quick response.
> 
> I’d like to have what others think.
> 
> Just one more note on my side: I think it depends a lot on the actual 
> deployment/application/use case. For instance, in some cases, 
> synchronization would be not needed at all; e.g., if the DetNet high 
> availability / high reliability feature is what is really needed for the 
> given case; or an asynchronous solution is used to achieve bounded low 
> latency.
> 
> Best regards,
> 
> Janos
> 
> *From:*qiangli (D) <[e-mail] <mailto:[e-mail]>>
> *Sent:* Wednesday, June 26, 2019 11:29 AM
> *To:* Janos Farkas <[e-mail] 
> <mailto:[e-mail]>>
> *Cc:* [e-mail] <mailto:[e-mail]>; 
> [e-mail] 
> <mailto:[e-mail]>; [e-mail] 
> <mailto:[e-mail]>; Liang GENG <[e-mail] 
> <mailto:[e-mail]>>
> *Subject:* RE: draft-geng-detnet-requirements-bounded-latency-02 revised 
> for comments
> 
> Hello Janos,
> 
> Thanks for your kindly remind and comment. I copied the Req. 2.2 text as 
> follows for easy check. The current version doesn’t contain any solution 
> and details as you requested. The reason that why we want to know what 
> degree of clock jitter & wander DetNet can tolerate, is to detail the 
> current text. According to your reply, I understand that DetNet just 
> simply uses what is available.  So maybe we can simply list some 
> existing standards here, no need to further specify more details. What 
> do you think.
> 
> ==========================================================
> 
> 2.2.2.  Sub-requirement 2.2: Should tolerate clock jitter & wander
> 
>          within a clock synchronous domain
> 
>     DetNet domain itself can be time synchronous or asynchronous,
> 
>     depending on the technology selection of different operators.  Even
> 
>     within a time synchronous domain, the synchronized clocks may also
> 
>     experience jitter & wander, the mechanisms adopted by DetNet should
> 
>     be able to tolerate a certain degree of clock jitter & wander.
> 
> ==========================================================
> 
> Best regards,
> 
> Cristina QIANG
> 
> *From:*Janos Farkas [mailto:[e-mail]]
> *Sent:* Wednesday, June 26, 2019 4:28 PM
> *To:* qiangli (D) <[e-mail] <mailto:[e-mail]>>
> *Cc:* [e-mail] <mailto:[e-mail]>; 
> [e-mail] 
> <mailto:[e-mail]>; [e-mail] 
> <mailto:[e-mail]>; Liang GENG <[e-mail] 
> <mailto:[e-mail]>>
> *Subject:* RE: draft-geng-detnet-requirements-bounded-latency-02 revised 
> for comments
> 
> Hi Cristina,
> 
> My understanding of the consensus of the WG based on the Architecture 
> document is that synchronization is acknowledged to be important; 
> however, it is not the job of DetNet to specify the details, solutions, 
> etc.; DetNet just uses what is available, specified by other standards.
> 
> Best regards,
> 
> Janos
> 
> *From:*detnet <[e-mail] <mailto:[e-mail]>> 
> *On Behalf Of *qiangli (D)
> *Sent:* Wednesday, June 26, 2019 5:33 AM
> *To:* [e-mail] <mailto:[e-mail]>
> *Cc:* [e-mail] 
> <mailto:[e-mail]>; [e-mail] 
> <mailto:[e-mail]>; Liang GENG <[e-mail] 
> <mailto:[e-mail]>>
> *Subject:* Re: [Detnet] 
> draft-geng-detnet-requirements-bounded-latency-02 revised for comments
> 
> Hi all,
> 
> The Req. 2.2 discusses that DetNet should be able to tolerate a certain 
> degree of clock jitter & wander even within a time synchronous domain. 
> We would like to know if you agree or disagree with this requirement. If 
> you think this requirement is necessary, then to what degree of clock 
> jitter & wander do you expect?
> 
> BTW, we are going to ask for WG adoption for this document in IETF 105 
> meeting. That’s will be greatly appreciated if you can share your 
> comments to help us further improve this draft.
> 
> Best regards,
> 
> Cristina QIANG
> 
> *From:*detnet [mailto:[e-mail]] *On Behalf Of *qiangli (D)
> *Sent:* Monday, June 17, 2019 4:11 PM
> *To:* [e-mail] <mailto:[e-mail]>
> *Cc:* [e-mail] 
> <mailto:[e-mail]>; [e-mail] 
> <mailto:[e-mail]>; Liang GENG <[e-mail] 
> <mailto:[e-mail]>>
> *Subject:* Re: [Detnet] 
> draft-geng-detnet-requirements-bounded-latency-02 revised for comments
> 
> Hi all,
> 
> This version has collected 7 requirements, and divided these 
> requirements into optional (SHOULD) and mandatory (MUST) two types as 
> following shows. We authors would like to know if this requirement list 
> is complete, and if the classification is appropriate or not.  Your 
> review and comments are highly appropriated.
> 
> ==========================
> 
> Req. 1: Must support the dynamic creation, modification and deletion of 
> deterministic services
> 
> Req. 2.1: Should support asynchronous clocks across domains
> 
> Req. 2.2 : Should tolerate a certain of clock jitter & wander within a 
> clock synchronous domain
> 
> Req. 3: Must support Inter-Continental propagation delay
> 
> Req. 4: Should have self-monitoring capability
> 
> Req. 5: Should be robust against denial of service attacks
> 
> Req. 6: Must tolerate failures of links or nodes and topology changes
> 
> Req. 7: Must be scalable
> 
> ===========================
> 
> Best regards,
> 
> Cristina QIANG
> 
> *From:*Liang GENG [mailto:[e-mail]]
> *Sent:* Tuesday, June 11, 2019 11:53 AM
> *To:* [e-mail] <mailto:[e-mail]>
> *Cc:* Black, David <[e-mail] <mailto:[e-mail]>>; 
> [e-mail] <mailto:[e-mail]>; 
> [e-mail] 
> <mailto:[e-mail]>; qiangli (D) 
> <[e-mail] <mailto:[e-mail]>>
> *Subject:* draft-geng-detnet-requirements-bounded-latency-02 revised for 
> comments
> 
> Dear all,
> 
> Since IETF 104, we have carefully revised 
> draft-geng-detnet-requirements-bounded-latency-02 according to received 
> comments. The latest 02 version was uploaded and available online 
> https://datatracker.ietf.org/doc/draft-geng-detnet-requirements-bounded-latency/. 
> 
> 
> This new version collects more technical, operational and management 
> requirements of deploying deterministic latency service on layer 3 
> networks from the perspective of various service providers.
> 
> Comments are welcome!
> 
> Best regards,
> 
> Liang Geng on behavior of co-authors
> 
> 
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