RE: Side Effects of SUBSCRIBE are Harmful (was RE: [Sipping] RE: I-D ACTION:draft-culpepper-sipping-app-interact-reqs-00.txt)
"Fairlie-Cuninghame, Robert" <rfairlie@nuera.com> Mon, 06 May 2002 20:57 UTC
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From: "Fairlie-Cuninghame, Robert" <rfairlie@nuera.com>
To: "'eburger@snowshore.com'" <eburger@snowshore.com>
Cc: sipping@ietf.org
Subject: RE: Side Effects of SUBSCRIBE are Harmful (was RE: [Sipping] RE: I-D ACTION:draft-culpepper-sipping-app-interact-reqs-00.txt)
Date: Mon, 06 May 2002 13:33:19 -0700
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Hi Eric, I agree. In fact I'm glad you say that as it reinforces an idea I've been toying with over the last few days. I think that it would actually be good to represent ALL user interface components (conforming to this framework) as SIP sessions. There are a number of reasons I think this might be a good idea: - Media-based UI components can then be treated the same as presentation- or input- based components. - Since it has been suggested that all virtual user interfaces MUST be associated with a SIP session, it actually makes things a lot cleaner if all UI components are themselves SIP sessions. For instance, a user that initiates an application interaction session using a media-based component (e.g., speaker+microphone) may later wish to switch to web-based interaction and hangup the handset. This is easily accomplished if both components are SIP sessions and the virtual user interface is associated with either/both sessions. - Additionally, application interactions do not need to be initiated with media-based (or empty "placeholder") SIP sessions. For instance, an application can initiate an interaction session with a VoiceXML-only interface. - A user wants/needs to know what entities are listening to their actions and input. From a security point of view (and more importantly human-factor POV), it is a lot easier to compare apples to apples. For instance, the user can see that the SIP sessions for the media-based component (e.g. speaker+microphone), presentation-based (e.g. web-page), input-based (e.g. dialpad) components are all associated to the same application. [Rather than comparing SIP sessions to subscriptions to arbitrary markups]. - SIP sessions are time-bounded so that applications should not be able to "lurk" in the background after an application session has finished. - By placing all UI components in a SIP session, applications should be able to update and close created user interface components. This framework also fits very nicely (in fact almost transparently) into the SIP framework. An application that wants to interact with a device (using this framework) simply requests that the device issue a virtual user interface identifier when establishing the initial SIP session. To add additional components to the VUI, the application uses the received virtual user interface identifier (which could even be a Contact-style URL). Now the problem is almost reduced to defining SIP payload formats for the user interface components [e.g., markup reference in INVITE message body]. Comments? Cheers, Robert. > -----Original Message----- > From: Eric Burger [mailto:eburger@snowshore.com] > Sent: 06 May 2002 16:24 > To: Fairlie-Cuninghame, Robert > Cc: sipping@ietf.org > Subject: Side Effects of SUBSCRIBE are Harmful (was RE: [Sipping] RE: > I-D ACTION:draft-culpepper-sipping-app-interact-reqs-00.txt) > > > Mumblings I've been hearing include the thought of using the SUBSCRIBE > method to request a device to do something, like play a > prompt, prompt and > collect digits, and so on. > > This is bad, verging on EVIL. Let us look at the definition > of SUBSCRIBE, > from Section 4.1 of draft-ietf-sip-events-04: > > The SUBSCRIBE method is used to request current state and state > updates from a remote node [Notifier]. > > > SUBSCRIBE is supposed to be a non-invasive method. With one > exception, > SUBSCRIBE is not supposed to modify the state of the > Notifier. Starting a > prompt play, displaying a screen, or a prompt & collect operation most > definitely changes the state of the Notifier. > > The one exception is (obviously) the Notifier responds to the > SUBSCRIBE > request. If there is a non-zero Expires, the Notifier needs > to remember to > update the Subscriber. Other than that, SUBSCRIBE should > (MUST?) not have > side effects on the Notifier. > > > With respect to the comment below, a session is infinitely > more appropriate > for the interaction model. > > > -----Original Message----- > From: sipping-admin@ietf.org [mailto:sipping-admin@ietf.org]On Behalf Of Fairlie-Cuninghame, Robert Sent: Friday, April 26, 2002 4:59 AM To: 'jdrosen@dynamicsoft.com' Cc: 'sipping@ietf.org' Subject: [Sipping] RE: I-D ACTION:draft-culpepper-sipping-app-interact-reqs-00.tx t [snip] I don't see any reason that it wouldn't be possible to place the markup in a subscription .... or rather, I think perhaps a session is more appropriate than a subscription for this model. [snip] _______________________________________________ Sipping mailing list https://www1.ietf.org/mailman/listinfo/sipping This list is for NEW development of the application of SIP Use sip-implementors@cs.columbia.edu for questions on current sip Use sip@ietf.org for new developments of core SIP
- RE: Side Effects of SUBSCRIBE are Harmful (was RE… Fairlie-Cuninghame, Robert
- Re: Side Effects of SUBSCRIBE are Harmful (was RE… Paul Kyzivat