Re: [Detnet] Questions about the Networks in DetNet charter

[Gyan Mishra <[e-mail]>]

Thank you Ethan for the history of Detnet!!

Kind Regards

Gyan

On Mon, Jul 6, 2020 at 10:36 PM Grossman, Ethan A. <[e-mail]> wrote:

> Hi Gyan,
> Gyan wrote:
>     > Also it does state in the charter but how was the WG name Detnet
> history?
> Lou wrote:
>     I'm not sure what the question is here.
>     https://datatracker.ietf.org/wg/detnet has the history and record for
>     past meetings and activities.
>
> If you are asking about the history of how the DetNet workgroup came to
> be, awhile ago I wrote up a brief summary from my perspective, which I can
> paraphrase here:
> ---------------------------------------
> In 2013 I became my employer's Technical Representative to the Avnu
> Alliance, an industry group dedicated to propagating the AVB technology. At
> that time Avnu had a “Pro AV” (Professional Audio and Video) subgroup that
> I joined, and also around that time the AES67 standard was introduced,
> which was the start of the broadcast industry’s interest in using packet
> based IP/Ethernet networks to replace dedicated point-to-point HW
> technologies for audio and video in broadcast production. It became clear
> to us in Avnu that we needed to figure out how to access the AVB services
> from the IP layer.
>
> The broadcast industry did a formal “gap analysis” about what was needed
> to transition the whole broadcast industry to packet-based technologies,
> and we at Avnu submitted a response pitching AVB as a useful technology.
> They basically replied that a LAN technology didn’t solve many of their
> connectivity use cases, they needed an IP based solution, regardless of
> whether the performance was guaranteed or not.
>
> Then Cisco sent Norm Finn to join Avnu Alliance, and he realized that we
> (i.e. Avnu) had to go to the IETF to address this. So he organized a BOF
> (at IETF 93 in Prague in 2015) in which he issued a call for use cases for
> deterministic IP networking, and various people presented the core use
> cases that eventually became the core of RFC8578 (DetNet Use Cases),
> including the Pro Audio and Video use case that I co-authored. I didn’t
> attend that BOF, but I shortly thereafter became editor of the DetNet Use
> Cases draft, and dropped my participation in Avnu to devote my time to
> DetNet.
> --------------------------------------
>
> Hope that helps.
> Ethan.
>
> -----Original Message-----
> From: Lou Berger <[e-mail]>
> Sent: Monday, July 6, 2020 12:21 PM
> To: Gyan Mishra <[e-mail]>
> Cc: [e-mail]; [e-mail]
> Subject: Re: [Detnet] Questions about the Networks in DetNet charter
>
>
> On 7/5/2020 10:35 PM, Gyan Mishra wrote:
> > Detnet WG
> >
> > I did not hear back anything on this question I had so was just
> > wondering on the correlation between Detnet and non ECMP type flows.
>
> Hi,
>
> multiple documents recommend against use of ECMP, e.g.,
> draft-ietf-detnet-data-plane-framework:
>
>
>           3.5.1.5
>           <
> https://tools.ietf.org/html/draft-ietf-detnet-data-plane-framework-06#section-3.5.1.5
> >.
>           Load sharing
>
>
>
>     Use of packet-by-packet load sharing of the same DetNet flow over
>     multiple paths is not recommended except for the cases listed above
>     where PREOF is utilized to improve protection of traffic and maintain
>     order.  Packet-by-packet load sharing, e.g., via ECMP or UCMP,
>     impacts ordering and possibly jitter.
>
> also, see https://www.google.com/search?q=draft-ietf-detnet+ecmp
>
> >
> > Also it does state in the charter but how was the WG name Detnet history?
>
> I'm not sure what the question is here.
> https://datatracker.ietf.org/wg/detnet has the history and record for
> past meetings and activities.
>
> Lou
>
> >
> > Kind Regards
> >
> > Gyan
> >
> > On Sun, Jun 28, 2020 at 6:51 PM Gyan Mishra <[e-mail]
> > <mailto:[e-mail]>> wrote:
> >
> >
> >     Deterministic networking by definition means the inbound and
> >     outbound paths use the same set of nodes and links for the flow.
> >
> >     So generally that means no ECMP per packet or per flow as IP ECMP
> >     is traditionally an XOR source/destination hash and so is deemed
> >     non deterministic predictable path taken by a flow.
> >
> >     Thanks
> >
> >     Gyan
> >
> >     On Sun, Jun 28, 2020 at 6:17 PM Gyan Mishra <[e-mail]
> >     <mailto:[e-mail]>> wrote:
> >
> >
> >         My last paragraph related to my question fixed.
> >
> >         I noticed in the charter or RFC 8578 does not mention non ECMP
> >         routing as deemed deterministic routing used in Detnet.
> >
> >         Thanks
> >
> >         Gyan
> >
> >         On Sun, Jun 28, 2020 at 6:01 PM Gyan Mishra
> >         <[e-mail] <mailto:[e-mail]>> wrote:
> >
> >
> >             I had a generic question related to the Detnet WG charter.
> >
> >             So I understand the focus of latency and jitter time
> >             sensitive applications such as voice and video over any
> >             single administrative domain which is covers am any
> >             carriers network including RAN 4G/5G.  Am good with all that.
> >
> >             To me the term “deterministic” from a network routing
> >             perspective historically precluded ECMP flow based load
> >             balancing or for example vxlan source port entropy IP ECMP
> >             load balancing.   Since IP ECMP load balancing is all flow
> >             based technically UDP voice and video flows are not
> >             impacted as IP ECMP is prevalent in most all providers and
> >             enterprises.  In the past, IP per packet load existed and
> >             that reeked havoc with voice and video UDP RTP based flows
> >             out of order packets.  Since then most vendors due to
> >             issues with per packet load balancing over multiple paths
> >             have been eliminated.
> >             In my mind anything other then per packet load balanced
> >             flows is deterministic.
> >
> >             Deterministic routing I would think means in the simplest
> >             sense a non load balanced single path with no ECMP along
> >             the entire path.  Another way to look at is that you can
> >             see the flow along any hop in the path if you did a packet
> >             capture where non deterministic path for a flow that would
> >             not be possible.
> >
> >             I noticed in the charter it does mention ECMP Verdi’s not
> >             or in RFC 8578.
> >
> >             What does the deterministic mean in the context of the WG
> >             framework as it does not seem related to deterministic
> >             routing.
> >
> >
> >             Kind Regards
> >
> >             Gyan
> >
> >             On Sun, Jun 28, 2020 at 5:35 PM Janos Farkas
> >             <Janos.Farkas=[e-mail]
> >             <mailto:40ericsson.com@dmarc..ietf.org>> wrote:
> >
> >                 Hi Quan.
> >
> >                 This was my previous response.
> >
> >                 Best regards,
> >
> >                 Janos
> >
> >                 *From:* Janos Farkas
> >                 *Sent:* Monday, June 22, 2020 10:54 AM
> >                 *To:* [e-mail]
> >                 <mailto:[e-mail]>
> >                 *Cc:* [e-mail]
> >                 <mailto:[e-mail]>; [e-mail]
> >                 <mailto:[e-mail]>; [e-mail]
> >                 <mailto:[e-mail]>
> >                 *Subject:* RE: Questions about the Networks in DetNet
> >                 charter
> >
> >                 Hi Quan.
> >
> >                 The main purpose of the cited sentence is to limit the
> >                 scope of the work to make it reasonable, i.e., not
> >                 trying to boil the ocean. Actually, the main message
> >                 is that DetNet is not for the big I Internet, but for
> >                 smaller networks than that.
> >
> >                 Networks like mobile backhaul are definitely in scope
> >                 of DetNet. It is actually explicitly there in the
> >                 DetNet Use Cases
> >                 https://tools.ietf.org/html/rfc8578#section-6.2.2.
> >
> >                 Best regards,
> >
> >                 Janos
> >
> >                 *From:* [e-mail]
> >                 <mailto:[e-mail]> <[e-mail]
> >                 <mailto:[e-mail]>>
> >                 *Sent:* Monday, June 22, 2020 4:29 AM
> >                 *To:* [e-mail]
> >                 <mailto:[e-mail]>; Janos Farkas
> >                 <[e-mail]
> >                 <mailto:[e-mail]>>; [e-mail]
> >                 <mailto:[e-mail]>
> >                 *Cc:* [e-mail]
> >                 <mailto:[e-mail]>
> >                 *Subject:* Questions about the Networks in DetNet charter
> >
> >                 Dear Chairs,
> >
> >                 I noticed that in DetNet Charter, it mentions that the
> >                 networks which WG foucs on as following shown.
> >
> >                 "The Working Group will initially focus on solutions
> >                 for networks that are under a single administrative
> >                 control or within a closed group of administrative
> >                 control; these include not only campus-wide networks
> >                 but also can include private WANs. The DetNet WG will
> >                 not spend energy on solutions for large groups of
> >                 domains such as the Internet."
> >
> >                 Could you please clarify that the WAN  such
> >                 as Metropolitan area network and Mobile backhaul
> >                 network is included in DetNet use case or not?
> >
> >                 And does the DetNet WG only focus on the small
> >                 networks similier with TSN?
> >
> >                 Your reply is important and appreciated.
> >
> >                 Thanks,
> >
> >                 Quan
> >
> >                 _______________________________________________
> >                 detnet mailing list
> >                 [e-mail] <mailto:[e-mail]>
> >                 https://www.ietf.org/mailman/listinfo/detnet
> >
> >             --
> >
> >             <http://www.verizon.com/>
> >
> >             *Gyan Mishra*
> >
> >             /Network Solutions A//rchitect /
> >
> >             /M 301 502-1347
> >             13101 Columbia Pike
> >             /Silver Spring, MD
> >
> >
> >         --
> >
> >         <http://www.verizon.com/>
> >
> >         *Gyan Mishra*
> >
> >         /Network Solutions A//rchitect /
> >
> >         /M 301 502-1347
> >         13101 Columbia Pike
> >         /Silver Spring, MD
> >
> >
> >     --
> >
> >     <http://www.verizon.com/>
> >
> >     *Gyan Mishra*
> >
> >     /Network Solutions A//rchitect /
> >
> >     /M 301 502-1347
> >     13101 Columbia Pike
> >     /Silver Spring, MD
> >
> >
> > --
> >
> > <http://www.verizon.com/>
> >
> > *Gyan Mishra*
> >
> > /Network Solutions A//rchitect /
> >
> > /M 301 502-1347
> > 13101 Columbia Pike
> > /Silver Spring, MD
> >
> >
> >
> > _______________________________________________
> > detnet mailing list
> > [e-mail]
> > https://www.ietf.org/mailman/listinfo/detnet
>
-- 

<http://www.verizon.com/>

*Gyan Mishra*

*Network Solutions A**rchitect *



*M 301 502-134713101 Columbia Pike *Silver Spring, MD