W3C home > Mailing lists > Public > public-web-and-tv@w3.org > August 2011

Re: [HOME_NETWORK_TF] Comments on "Application Communication" requirement

From: Matt Hammond <matt.hammond@rd.bbc.co.uk>
Date: Mon, 29 Aug 2011 11:58:47 +0100
To: "Jean-Claude Dufourd" <jean-claude.dufourd@telecom-paristech.fr>, "public-web-and-tv@w3.org" <public-web-and-tv@w3.org>, "Bob Lund" <B.Lund@cablelabs.com>, "Giuseppe Pascale" <giuseppep@opera.com>
Message-ID: <op.v0y139rvmko9fo@r44116>
Ah, I see - yes discovery is probably already covered. I'm happy with what  
you propose.

many thanks


Matt

On Mon, 29 Aug 2011 11:15:02 +0100, Giuseppe Pascale <giuseppep@opera.com>  
wrote:

> On Mon, 29 Aug 2011 11:59:30 +0200, Matt Hammond  
> <matt.hammond@rd.bbc.co.uk> wrote:
>
>> I think you are right - this needs separating into two requirements.
>>
>> I believe that what Bob originally suggested regarding "discovery" might
>> apply "application communication" too.  For example:
>>
>> "Application communication: Conforming specifications should provide a
>> means for applications running in different user-agents to discover each
>> other and exchange messages directly via the home network."
>>
>>
> There is a separate section/requirement for discovery.
> As is phrased now the requirement about discovery mention both services  
> and "application exposing services":
>
> http://www.w3.org/2011/webtv/wiki/HNTF/Home_Network_TF_Requirements#Service_Discovery
>
> ***
> Service Discovery:
> Conforming specifications should provide a means for applications to  
> discover devices and applications in the home network which advertise  
> services. Details of the advertising protocol are out of scope for this  
> document and the type and number of supported discovery protocols are  
> user agent dependent. Nevertheless conforming specifications should  
> provide a means for application to identify the type of discovered  
> services that are available and to search for services of a specific  
> type.
> ***
>
> I think is just a matter of semantics here: is an application that is  
> discoverable implicitly "exposing a service"? If so, then we may not  
> need a new requirement; if not, we may want to separate  
> discovery/communication of applications from discovery/communication of  
> services.
>
> Honestly I don't have a strong opinion.  One reason why we may want to  
> split this in 2 requirements could be that app-2-app discovery and  
> communication could probably generate slightly different requirements if  
> compared to app-2-service discovery & communication when going into the  
> actual specification work.
>
> In short I see 2 options:
> #1 we keep the requirement as quote above
> #2 we add to the requirement above another one that could look like this:
>
> ***
> Application Discovery:
> Conforming specifications should provide a means for applications  
> running in different user-agents to discover each other directly via the  
> home network. Details of the advertising protocol are out of scope for  
> this document.
> ***
>
> I would propose to go for option #2.
>
> /g
>
>>
>> many thanks
>>
>>
>>
>> Matt
>>
>>
>> On Sun, 28 Aug 2011 23:31:05 +0100, Giuseppe Pascale  
>> <giuseppep@opera.com>
>> wrote:
>>
>>> On Sun, 28 Aug 2011 21:49:33 +0200, Matt Hammond
>>> <matt.hammond@rd.bbc.co.uk> wrote:
>>>
>>>> Definitely agree with Bob that this requirement should be expressed in
>>>> terms of how there needs to be discovery in order to initiate
>>>> communication.
>>>>
>>>> Thinking about the use of the term 'services': should this be phrased
>>>> in terms of 'applications' throughout, rather than 'services'?
>>>> Communication with services is already covered by other requirements.
>>>> This particular requirement originated from the "Local Link for Web
>>>> Applications" use case[1]:
>>>>
>>>> http://www.w3.org/2011/webtv/wiki/HNTF/Home_Network_TF_Requirements#U14:_Local_Link_of_Web_Applications
>>>>
>>>
>>> Agree. It seems to me we need 2 requirements. We can leave the one  
>>> about
>>> "service communication" as phrased below, plus I would add the  
>>> following:
>>>
>>> "Application communication: Conforming specifications should provide a
>>> means for applications running in different user-agents to exchange
>>> messages directly via the home network."
>>>
>>> Bob, Matt, what do you think?
>>>
>>> /g
>>>
>>>> regards
>>>>
>>>>
>>>> Matt
>>>>
>>>> On Tue, 23 Aug 2011 16:08:04 +0100, Giuseppe Pascale
>>>> <giuseppep@opera.com> wrote:
>>>>
>>>>> On Mon, 22 Aug 2011 18:13:38 +0200, Bob Lund <B.Lund@cablelabs.com>
>>>>> wrote:
>>>>>
>>>>>> I agree but I think it should be stated in terms of access to
>>>>>> services discovered on the home network:
>>>>>>
>>>>>> "Service communication: Conforming specifications should provide a
>>>>>> means for a client to exchange messages directly via the home  
>>>>>> network
>>>>>> with services discovered in the home network."
>>>>>>
>>>>> As discussed I changed this into
>>>>>
>>>>> "Service communication: Conforming specifications should provide a
>>>>> means for an application to exchange messages directly via the home
>>>>> network with services discovered in the home network."
>>>>>
>>>>> http://www.w3.org/2011/webtv/wiki/HNTF/Home_Network_TF_Requirements#Service_communication
>>>>>
>>>>> /g
>>>>>
>>>>>> Bob
>>>>>>
>>>>>>> -----Original Message-----
>>>>>>> From: public-web-and-tv-request@w3.org [mailto:public-web-and-tv-
>>>>>>> request@w3.org] On Behalf Of Jean-Claude Dufourd
>>>>>>> Sent: Monday, August 22, 2011 9:05 AM
>>>>>>> To: public-web-and-tv@w3.org
>>>>>>> Subject: Re: [HOME_NETWORK_TF] Comments on "Application
>>>>>>> Communication"
>>>>>>> requirement
>>>>>>>
>>>>>>> I strongly support this clarification about direct communication.
>>>>>>> Best regards
>>>>>>> JC
>>>>>>>
>>>>>>> On 22/8/11 16:44 , Giuseppe Pascale wrote:
>>>>>>> > On Sun, 21 Aug 2011 20:20:43 +0200, Matt Hammond
>>>>>>> > <matt.hammond@rd.bbc.co.uk> wrote:
>>>>>>> >
>>>>>>> >> Hi all,
>>>>>>> >>
>>>>>>> >> Apologies for this being a little later than I originally
>>>>>>> intended:
>>>>>>> >> as I mentioned in last week's conf call, I have a comment
>>>>>>> regarding
>>>>>>> >> the "Application Communication" requirement.
>>>>>>> >>
>>>>>>> >> Would it be helpful to clarify that this requirement is
>>>>>>> specifically
>>>>>>> >> intended to enable direct communication between applications?  
>>>>>>> This
>>>>>>> >> would be to distinguish it from an implementation that (for
>>>>>>> example)
>>>>>>> >> sent all communications through a cloud based relay or proxying
>>>>>>> service?
>>>>>>> >>
>>>>>>> >> For example: "Conforming specifications should provide a means  
>>>>>>> for
>>>>>>> >> applications to exchange messages directly via the home network
>>>>>>> with
>>>>>>> >> other applications running on a different user agent in the home
>>>>>>> >> network."
>>>>>>> >>
>>>>>>> >
>>>>>>> > Hi Matt,
>>>>>>> > thanks for raising this in writing.
>>>>>>> > I agree that several (all?) of the use cases we have discussed
>>>>>>> require
>>>>>>> > (preferably) a direct communication. I think this is pretty
>>>>>>> > uncontroversial and could add it right away to the requirement
>>>>>>> document.
>>>>>>> > Some of the use cases could actually be covered by an indirect
>>>>>>> > communication mechanism as well, so probably also that would be  
>>>>>>> in
>>>>>>> > scope. On other end such a mechanism may either not need
>>>>>>> (additional)
>>>>>>> > standardization or fall back to the a different discussion about
>>>>>>> which
>>>>>>> > services could be standardized.
>>>>>>> >
>>>>>>> > So in short I'm fine to re-word the requirement as you suggested  
>>>>>>> if
>>>>>>> > nobody objects.
>>>>>>> >
>>>>>>> > /g
>>>>>>> >
>>>>>>> >> regards
>>>>>>> >>
>>>>>>> >>
>>>>>>> >>
>>>>>>> >> Matt
>>>>>>> >
>>>>>>> >
>>>>>>>
>>>>>>>
>>>>>>> --
>>>>>>> JC Dufourd
>>>>>>> Directeur d'Etudes/Professor
>>>>>>> Groupe Multimedia/Multimedia Group
>>>>>>> Traitement du Signal et Images/Signal and Image Processing Telecom
>>>>>>> ParisTech, 37-39 rue Dareau, 75014 Paris, France
>>>>>>> Tel: +33145817733 - Mob: +33677843843 - Fax: +33145817144
>>>>>>>
>>>>>>
>>>>>>
>>>>>
>>>>>
>>>>
>>>>
>>>
>>>
>>
>>
>
>


-- 
| Matt Hammond
| Research Engineer, BBC R&D, Centre House, London
| http://www.bbc.co.uk/rd/
Received on Monday, 29 August 2011 10:59:51 UTC

This archive was generated by hypermail 2.4.0 : Friday, 17 January 2020 17:57:07 UTC