- From: Norifumi Kikkawa <Norifumi.Kikkawa@jp.sony.com>
- Date: Mon, 09 Jul 2012 09:53:09 +0900
- To: "Cathy.Chan@nokia.com" <Cathy.Chan@nokia.com>
- Cc: "public-web-intents@w3.org" <public-web-intents@w3.org>
Hi Cathy, Thank you for your response. I also think the document should indicate a single WebIntents service basically. I don't have a good example that people want to implement multiple WebIntents service. Therefore, I suppose that your restriction wouldn't hurt people's implementation. I just feel additional restriction over UPnP should be minimized in the document. I think people will not implement multiple WebIntents services even if the document doesn't prohibit it clearly. Since this is just my preference, I could be OK with introducing the restriction. Note that when a device has more than one services of the same serviceType, it just responds a number of types in SSDP. For example, a Device holding one A service and two B services will advertise only two messages standing for service A and service B. So multiple WebIntents service doesn't make a traffic busy. (But this is not my point.) Regards, Kikkawa On Sat, 7 Jul 2012 01:19:50 +0900 "Cathy.Chan@nokia.com" <Cathy.Chan@nokia.com> wrote: > It's true that a UPnP-enabled UA is not going to look at the content of the > UPnP description document. However, there are other implications of having > multiple instances of the UPnP WebIntents service in there. > > First, a UPnP device is required to send periodic NOTIFY messages for each > service listed in the UPnP description document. Similarly, it is required > to send search response messages for each matching service listed there. > Each additional instance of the UPnP WebIntents service results in more such > messages in the network, and more messages for the UPnP-enabled UAs to > process (or at the very least, inspect). If there are other regular UPnP > entities (control points) in the network, they will be burdened by the extra > messages as well. > > Additionally, while UPnP-enabled UAs have no interest in the UPnP > description document, other regular UPnP entities (control points) in the > network typically process description documents in their normal operations. > Having additional instances of the UPnP WebIntents service in these > documents also adds to the workload of such entities. > > As the creator of this almost-dummy UPnP service (the sole purpose of its > creation is to be able to do targeted SSDP searches) with full knowledge of > what it does and what it does not do, we have the responsibility (instead of > leaving it up to developers/implementers to do the right thing) of limiting > the impact it has on both the devices that we target at (UPnP-enabled UAs) > and those that we don't (all other UPnP entities on the network), and > network traffic in general. Thus I stand by my suggestion to prohibit > multiple instances of the UPnP WebIntents service in the UPnP description > document. > > - Cathy. > > > > -----Original Message----- > > From: ext Norifumi Kikkawa [mailto:Norifumi.Kikkawa@jp.sony.com] > > Sent: Friday, July 06, 2012 2:52 AM > > To: Chan Cathy (Nokia-CIC/Boston) > > Cc: public-web-intents@w3.org > > Subject: Re: Review of Web Intents addendum for local services > > > > Hello Cathy and all, > > > > I agree with Cathy, just with adding a comment. > > (The link is still dead...) > > > > As you mentioned, even a device supports more than one Intent actions, it > > does not have to enumerate more than one WebIntents serviceTypes. > > The text in the A.4 figure should be removed. > > I think this is enough as the document and it doesn't have to prohibit > multiple > > WebIntents serviceTypes explicitly because even if a device happens to > have > > multiple WebIntents serviceTypes, it doesn't make a client implementation > > more complex. I assume a client in the web intents scenario may not see > the > > content of UPnP description document. > > > > Best Regards, > > Kikkawa > > > > --------------------------------------------- > > Norifumi Kikkawa <Norifumi.Kikkawa@jp.sony.com> > > Section 1 > > Network Technology Dept. > > Information Technology Development Division > > System & Software Technology Platfotm > > Sony Corporation > > (TEL) +81 50 3750 3953 > > ----------------------------------------------- > > > > On Fri, 6 Jul 2012 05:10:51 +0900 > > "Cathy.Chan@nokia.com" <Cathy.Chan@nokia.com> wrote: > > > > > Here are my comments on the addendum that Claes uploaded last week. > > > (The link is dead as of today by the way.) > > > > > > 4.1.1 The actionList tags should be removed. The UDA requires that the > > > actionList must not be listed in the service description when there > > > are no actions. > > > 4.1.1 The text description says X_State is ui4 but it's in boolean in > > > the example. > > > 4.1.2 [[To support more than one Web Intents action the action strings > > > must be separated with one or more commas.]] > > > - This can be misinterpreted as multiple commas between two action > > strings. > > > s/one or more// > > > 4.1.3 [[The UPnP enabled device must store Web Intents documents for > > > the Web Intents Services the UPnP enabled device supports.]] > > > - "store" alone does not make it available to the UA. Change "store" > > > to "host" or "expose" or something else? > > > - Similarly with 4.1.4. > > > 4.2 Step 2. [[If the action.webintents.org header is present and does > > > not match the action attributes of the Services registered in the > > > retrieved Web Intents document the UPnP enabled User Agent silently > > > disregards the discovered Service.]] > > > - It's unclear which Service is referred to in "disregards the > > > discovered Service". I think this refers to a Web Intents service > > > listed inside the Web Intents document, especially in cases where the > > > Web Intents document includes multiple services, and not all of them > > > match the action.webintents.org header. This, however, is a different > > > use of "disregards the discovered Service" as in the previous > > > sentence, where Service refers to the entire M-SEARCH response/UPnP > > service. > > > - Ideally, the UA may choose to register all services (for future use) > > > but only present the matching one(s) in the picker. (see the next > > > point.) > > > 4.2 If a Web Intents document includes registration markup for > > > multiple services, does the UA register all the services or only the > > > matching service(s)? Step 4 implies the latter, but step 3 may be > > > interpreted to imply the former. > > > 4.2.1 s/continously listen/continuously listen to/ > > > 4.2.2 [[...it is *assumed* that UPnP enabled User Agents that comply > > > to this specification support Web Intents according to > > > [WEBINTENTS]...]] conflicts with the Conformance section where [[A > > > UPnP enabled User Agent *must* support Web Intents [WEBINTENTS].]] > > > 4.2.2 Why is UDA 1.1 referenced here while the rest of the document > > > refers to UDA 1.0? > > > 4.2.3 is non-normative but starts with a MUST statement. > > > A.4 The figure has a note [[To support more than one Web Intents > > > Service, add more service elements with different "serviceId" for the > > > Web Intents Services.]] In UPnP, multiple instances of a service is > > > used when those instances would have different state variable values, > > > respond to actions differently, etc. Since in this spec we already say > > > that the state variable is dummy and there are no actions, there's no > > > real reason to use multiple [UPnP] services. (Note that multiple Web > > > Intents services can be registered with a single Web Intents document > > > and therefore do not necessitate the use of multiple UPnP services.) I > > > would suggest prohibiting the use of multiple UPnP WebIntents services > > altogether, which may make implementations simpler. > > > This can be done at the beginning sentence of 4.1.1 [[The UPnP enabled > > > device must support the UPnP service which serviceType is > > > urn:schemas-webintents-org:service:WebIntents:1 ...]] - s/the UPnP > > > service/one UPnP service/ > > > > > > This may well be a matter of personal preference. Instead of > > > "UPnP-enabled device", I would suggest using either "Web Intents > > > enabled UPnP device" to highlight the Web Intents capability of such > > > devices, or simply UPnP device to be consistent with common usage. My > > > preference is the former, as it would also help distinguish these more > > > capable devices from "legacy" UPnP devices if/when we write new > > specifications to support those. > > > > > > - Cathy. > > > > > > --------------------------------------------- Norifumi Kikkawa <Norifumi.Kikkawa@jp.sony.com> Section 1 Network Technology Dept. Information Technology Development Division System & Software Technology Platfotm Sony Corporation (TEL) +81 50 3750 3953 -----------------------------------------------
Received on Monday, 9 July 2012 00:53:43 UTC