> On 05 Jun 2015, at 13:29, Mirja Kühlewind <[email protected]> 
> wrote:
> 
> Hi Michael,
> 
> see below.
> 
> 
> On 05.06.2015 11:05, Michael Welzl wrote:
>> 
>>> On 5. jun. 2015, at 10.12, Mirja Kühlewind 
>>> <[email protected]> wrote:
>>> 
>>> Okay, just to quickly clarify. In the charter only the word service is 
>>> used. We defined later on the words component and feature which are 
>>> currently not reflected in the charter. The part I've cited below, I think, 
>>> it should say components. However, it does not really matter because we 
>>> will in the current document first identify components and then discuss 
>>> features. In any case this document will not define a new interface.
>> 
>> I got that but I disagree about "it should say components" for the part in 
>> the charter: from the definition, the component is an implementation, not 
>> what is exposed to the application. I think the more important part is to 
>> capture what's exposed to the application. For example: SCTP has a component 
>> called "strong error detection (CRC32C)". TCP has a component called "error 
>> detection (checksum)". This is probably not exposed to the application as 
>> such by any of these protocols. I'll explain below why this makes it less 
>> important in my opinion...
> 
> I don't think that this decision is (in general) that easy. That's why we go 
> through the exercise of decomposing existing protocols into their components 
> and based on this information discuss what potentially could be exposed and 
> further reason about what should be exposed (because there are implications 
> for the application).
> 
> From my point of view this process it independent of the interface (not 
> matter if we talk about an abstract interface, a certain implementation or 
> what we want to have in future). However, looking at current interfaces will 
> probably help us to make the right decisions.
> 
>> 
>> 
>>> I'd also say that this is not the flag ship document (as stated by Joe). 
>>> The flagship document probably is the third item on the charter which then 
>>> will probably also talk about the interface in more detail (charter says on 
>>> the third doc: "This document will explain how to select and engage an 
>>> appropriate protocol ...").
>> 
>> Well, this first document is no less important, everything hinges on it.
>> 
>> So let's think of the future system we're envisioning here. Is it going to 
>> provide "error detection" as a service? Is it going to provide "strong error 
>> detection"?
>> 
>> When making these decisions, I think we'd first need to go through the list 
>> of things provided to applications by the protocols in what Joe calls the 
>> abstract API. Probably we won't find it there: it's a static property of the 
>> protocols AFAIK. So, next, we go through all the static properties to figure 
>> out what we need to expose. Then, the question becomes: should a TAPS system 
>> decide for or against SCTP based on the level of error protection? Is this a 
>> basis for deciding for this or the other protocol?
>> 
>> These are important decisions but I think they are secondary, whereas what 
>> the protocols now explicitly offer is primary - because it would be very 
>> strange not to offer what is being offered today. We can decide to not 
>> expose "level of error protection" and give the TAPS more freedom in 
>> choosing the protocol; given that the goal is to stop connection 
>> applications to specific protocols, we CAN do that.
>> 
>> That's why I think the service is more important than the component, and 
>> that's why I'm on Joe's side here.
> 
> I didn't say anything about the importance of anything. I think all three 
> documents and and all kind of transport 'things' we talk about are important. 
> And most important is the process of getting things 'decomposed' correctly 
> and discussed in the right document at the right time.
> 
> What I wanted to say is that people who later on read these docs (because 
> they want to use taps), probably only read the third doc, maybe the second, 
> and very likely will only read this document if they already have read the 
> other two and would like have additional information.
> 
> I do have the feeling that parts of what Joe wants to discuss should however 
> be in the third doc. And therefore I think that the current first doc is not 
> the taps flagship doc because for me a flagship doc (and we probably need to 
> define this term ;-) ) is the doc that you point people to as the first thing 
> to read after the work was finished...?
> 
> All in all, I actually think that we are on the same side here (and right at 
> this point we don't need too much further discussion). Brian and I are in the 
> process of marking a better distinction on components and feature than what 
> is given in the lists in the current version. I believe the current, very 
> sloppy handing of these lists is where most on the confusion (and potentially 
> disagreement) comes from and I hope that discussion can be more focused soon 
> as we have submitted the next revision.

Cool, thanks for the work you folks put into this! And have a nice weekend,
Michael

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