Re: [Coin] 答复: Agenda for today

["Dirk Kutscher" <[e-mail]>]

Hi,

More generally, “computing in the network” has the potential to open 
new perspectives on the relationship of “hosts”, “network” as 
well as on layers, i.e., required services and functional 
modularization.

I don’t think it’s helpful if we constrain ourselves to 1990s 
textbook categories (such as “L3”, “L4”). These categories were 
not god-given anyway — they just helped in designing systems at a time 
and explaining them…

IMO, one of the COIN objectives should be to propose/define new 
categories for functional composition that help to us to describe the 
relevant COIN scenarios.

Just as an example, if we consider a set of distributed data sources and 
processing/aggregation functions a COIN use case, what would be the 
“L4” protocol? What would be the “end-to-end” service?

An example at the other end of the spectrum could be a set of 
programmable network nodes that get programmed by some SDN controller to 
achieve a certain packet forwarding behaviour (for example, multicast 
distribution).

What abstraction could be useful to describe these two use cases in one 
framework? (And is there any value in trying to find them?) IMO these 
are good challenges for COIN.

And, in that context, SDN frameworks, control protocols (such as 
OpenFlow), programming languages (such as P4) are IMO just tools that 
could be useful in one or the other scenario — just like execution 
environments are tools — they should not define the concepts and 
decomposition categories we talk about here.

Summarizing, I agree to DirkT that COIN should go beyond programmable 
routing and forwarding, and when doing that, we have to rethink 
traditional definitions of hosts, networks etc.

Cheers,
Dirk






On 19 Jun 2019, at 17:52, Marie-Jose Montpetit wrote:

> (Chair hat off):
> I actually agree with Dirk. I would not want to limit computing to the 
> routing and forwarding. We have discussed meta data processing in the 
> past for example. And host is generic enough.
>
> mjm
> Marie-Jose Montpetit, Ph.D.
> [e-mail]
> [e-mail]
> [phone]
> @SocialTVMIT
>
>
>
>> On Jun 19, 2019, at 11:49 AM, Dirk Trossen 
>> <[e-mail]> wrote:
>>
>> Hemant
>>
>> I was under the impression the RG would target computing in networks 
>> (COIN). I didn't see this as limited to essentially programmable 
>> routing and forwarding. If indeed the group targets the intersection 
>> of computing and communication, as expressed early in the charter, 
>> the removal of any mentioning of host is rather questionable to me.
>>
>> Best
>>
>> Dirk
>> From: [e-mail] <mailto:[e-mail]> <[e-mail] 
>> <mailto:[e-mail]>>
>> Sent: Wednesday, June 19, 2019 1:02:30 PM
>> To: 'Hejianfei (Jeffrey)'; Dirk Trossen; 'Marie-Jose Montpetit'; 
>> [e-mail] <mailto:[e-mail]>
>> Subject: RE: [Coin] 答复: Agenda for today
>>
>> Please see in line below.
>>
>> From: Coin <[e-mail] <mailto:[e-mail]>> On 
>> Behalf Of Hejianfei (Jeffrey)
>> Sent: Tuesday, June 18, 2019 10:40 PM
>> To: Dirk Trossen <[e-mail] 
>> <mailto:[e-mail]>>; Marie-Jose Montpetit 
>> <[e-mail] <mailto:[e-mail]>>; [e-mail] 
>> <mailto:[e-mail]>
>> Subject: [Coin] 答复: Agenda for today
>>
>> Hi Dirk,
>>
>> Thank you for your comments for the charter. Marie-Jose, Eve and me 
>> discussed these in our bi-weekly co-chair meeting, and the response 
>> below (with [JEM]) reflects what we three think. Of course, it is how 
>> this GROUP feel and think that decides what this group should do…
>>
>> JEM(Jeffrey, Eve, Marie-Jose)
>>
>> 发件人: Coin [mailto:coin-bounces@irtf..org 
>> <mailto:coin-bounces@irtf..org>] 代表 Dirk Trossen
>> 发送时间: 2019年6月7日 21:51
>> 收件人: Marie-Jose Montpetit <[e-mail] 
>> <mailto:[e-mail]>>; [e-mail] <mailto:[e-mail]>
>> 主题: Re: [Coin] Agenda for today
>>
>> Marie-Jose, all,
>>
>> As for the charter, some comments:
>> 1.      Item 1 mentions the term ‘network functions’ as the scope 
>> of research. Is this limitation to ‘network function’ intended?
>> [JEM] After all, we are talking about “in-network” functions. 
>> “Network function” is still ok, only if we don’t limit “ 
>> network function” to simply forwarding.
>> 2.      As mentioned in the call, item 2 (use cases) is a method 
>> useful not just for requirements analysis (which is solution 
>> oriented) but also for scoping of work, i.e., what is in scope of the 
>> RG and what is not
>> [JEM] If we discuss how use cases are related to the scope, we may 
>> need to clarify two levels: networks and applications above. We are 
>> addressing different sectors of networks, mainly three now: DCN, 
>> industrial networks and Edge(with Cloud continuum). And there are 
>> different applications related to these three sectors, such as video 
>> streaming, immersive AR/VR, autonomous/connected vehicles, industrial 
>> IoT.  We need to take care of the relationship between network 
>> sectors and applications. One potential and ambitious objective is to 
>> explore the common architecture or abstraction for these three, but 
>> an even less ambitious reason to address all three in this research 
>> group is that these sectors can learn from each other. E.g. the metro 
>> network connecting edges has the similarity with DCN connecting 
>> servers(e.g how to better convey the distributed computing system), 
>> while the experience in in-network control from smart factory may be 
>> inspiring for the mission critical services in edge networking in 
>> smart city. It is up to the group to decide based on their interest 
>> if we address all these three or focus some of them. But to us three, 
>> all three are related and interesting.
>> 3.      Item 2 states “Identify potential benefits to these 
>> networks from in-network functionality” which confuses me a bit in 
>> terms of ‘these networks’ as a focus here. Item 3 does recognize 
>> OTOH that we consider placement of compute ‘even in end devices’. 
>> My main concern goes back to the feedback I received in the past from 
>> people who see ‘the network’ ending at the last link to the end 
>> device. If we see a continuum of providing services across devices 
>> that include end devices as well as ‘in-network resources’ then 
>> the benefits are not limited to ‘the network’ only. I suggest 
>> simply removing ‘to these networks’ from the statement
>> [JEM] Yes, we think “simply removing ‘to these networks’ from 
>> the statement” is fine.
>> 4.      I understand item 4 having arisen from the interactions with 
>> the transport area but I wonder why we do not include ‘routing’ 
>> into the list here, unless we assume ‘transport’ does include 
>> ‘routing’. On the other hand, item 3 includes ‘new protocol 
>> designs’ so it seems that the unique point about item 4 is in fact 
>> the security and privacy part so maybe rewording item 4 to 
>> “research on new privacy and security mechanisms required to enable 
>> in-network compute” would be best?
>> [JEM] Yes,  we agree that  probably moving “transport protocol” 
>> to item3 can resolve the ambiguousness. Then the item 3 may looks 
>> like: “Research on novel architectures, data-plane abstractions and 
>> new networking/transport protocols designs to…” The reason behind 
>> current text:  networking is layer-2/3, transport is layer-4, so the 
>> current item3 is emphasize the layer-2/3 as the data plane in the 
>> switches and routers, while transport are at the host side. But Dirk 
>> is right, it is confusing to separate “ transport” from “ 
>> network”.
>> Last question for me to understand the scope: what is a programmable 
>> network device? An SDN or P4 switch? Or networked laptop? Or my 
>> mobile device? Or all of it? Throughout the charter text, we talk 
>> about programmability for ‘devices’, ‘switches’ as well as 
>> ‘networks’. Maybe if we answer the question for ‘device’, we 
>> can provide good answers to the others?
>> [JEM] A programmable “network device” can be:  a programmable 
>> switch, a router with Network Processor Units(NPUs) which is 
>> typically also programmable but not as open as a P4 switch, a 
>> soft-router/switch with X86 or ARM in the context of NFV, or 
>> something made of FPGA, and so on.
>>
>> [HS] Minor point.  Please see https://github.com/hesingh/p4-info 
>> <https://github.com/hesingh/p4-info> which lists NPU, FPGA, and 
>> generic computer as all being programmable using P4.
>>
>> Logically we differentiate “network device” from 
>> “host”(“the network’ ending at the last link to the end 
>> device”) , but physically a network node and a host may be 
>> implemented in the same real hardware: these mobile phones/laptops 
>> can function as “network nodes” besides “hosts”. This is not 
>> what we try to emphasize at this stage, but it is possible. That’s 
>> why we state “’even’ in the end-user device” in item 3.
>>
>> [HS] When an interface on a router acquires an IP/IPv6 address, the 
>> interface is a host.  I would elide all mention of host, mobile 
>> device, laptop, etc.  Just stick to “computing in network”.  The 
>> network may be connecting a laptop, cell phone, router, switch, 
>> refrigerator, smart speaker, whatever…
>>
>> Hemant


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