RE: [XCON] Whisper vs. Sidebar

["Noa Kissilov" <NoaK at radvision.com>]

Hi,

Currently in the conference policy document there is a reflection of the
sidebars that exist in a conference. I think we should take this into
consideration when talking about implementing sidebars and whispers in
the same way - the difference is not only in user interface. 

    noa.


-----Original Message-----
From: xcon-bounces at ietf.org [mailto:xcon-bounces at ietf.org] On Behalf Of
Markus.Isomaki at nokia.com
Sent: Tuesday, November 16, 2004 10:22
To: br at brianrosen.net; oritl at microsoft.com; xcon at ietf.org
Subject: RE: [XCON] Whisper vs. Sidebar


Brian,

I'm not only talking about the user interface, but also considering the
difference between implementing one-shot communication (whisper) vs.
session-type communication (sidebar) within the context of a conference.
I agree that it is possible to use the same technical mechanism to
implement both (i.e. even for one-shot whispers first setup a "sidebar",
send the "media", and tear the sidebar down - with having some
parameters telling that the sidebar in this case is just for one-shot
communication), but currently I don't think that is the most efficient
way. 

And true - I expect whisper and sidebars to be different in the UI, in
the same way as SIP MESSAGE vs. MSRP are probably different in most UIs.


More comments inline.

> -----Original Message-----
> From: xcon-bounces at ietf.org [mailto:xcon-bounces at ietf.org]On Behalf Of

> ext Brian Rosen
> Sent: 16 November, 2004 02:37
> To: 'Orit Levin'; Isomaki Markus (Nokia-TP/Espoo); xcon at ietf.org
> Subject: RE: [XCON] Whisper vs. Sidebar
> 
> 
> Let's go over this slowly, because I'm confused.  Of course,
> that happens
> often enough but...
> 
> If a sidebar is public, what does that mean?  Anyone can determine if 
> anyone else is in a sidebar, and with whom?  Can you cite something 
> like it?  That seems very unlikely to me, but I suppose.
> 

Well, I think this just has to be determined using a bunch of
permissions, e.g. who is able to join the sidebar, and who is able to
see that the sidebar exists. "Public" is probably too simplified here, I
think we should really define the permissions (unless we think that
there is some default that always works).

> Let's say it is allowed to be a policy issue.  If there is a policy
> mechanism that allows such a thing, why would a whisper be 
> different?  That
> is, why would you not allow a policy decision on whisper if 
> you allow a
> policy decision on a sidebar?
> 

Right. I think it is perfectly valid to have policies (permissions) on
whispers as well, but at least to me the default where no-one can
see/know if others are whispering seems intuitive. I don't think
sidebars in general are as clear.  

> Clearly, a whisper is "explicitly formed", right?  What could 
> it possibly
> mean to not be explicitly formed?
> 
> Now then there is the "clear communications context".  What 
> does that mean?
> That it has a URI?
> 
> Let's ask, why you want a URI for a sidebar?  The one thing 
> that has been
> mentioned is so you can INVITE a participant to a sidebar who 
> is not in the
> main conference.  I suppose that wouldn't make sense for a 
> whisper, but are
> there any other reasons for a URI?  Is there actual harm in 
> having a URI for
> whisper?  Are there advantages?  Is there anything else you 
> think is part of
> a "clear communications context" that applies?
> 

In practice I expect the most effective design to be such that the
conference creation already creates enough state/context for anybody to
send whispers to anybody. This would be good since no additional
"signaling" would then be needed just to setup and tear down this type
of context each time someone wants to send a single "message". On the
other hand I expect sidebar creation to need some signaling steps in
order to setup the state/context for it. 

I have analysed this mainly from messaging/MSRP point of view, where it
is very clear that it is rather easy to keep the state needed for
any-to-any whispering as part of the conf state. It may very well be
that the benefit is not that clear for voice or video. 

> A "one shot IM" is an interesting analogy.  Do you not really 
> mean "Push to
> Talk"?  Implementers of PTT have discovered that they 
> actually do need a
> "clear communications context" for such things, primarily so 
> that resources
> are reserved for when they are needed.  Would that not apply 
> to a whisper?
> 

As said, I do believe that at least for messaging/MSRP such resources
can be reserved for the whole duration of the conference without needing
to explicitly reserve them when they are used. In fact I think the need
for state is pretty small since you can carry most of that (e.g.
recipients) within the message (MSRP SEND) itself.

I haven't seen a PTT system where whispering or sidebars would be
implemented for conferences.

> Do you think a whisper is always "Push to Talk"?  Is it worth 
> creating a
> special mechanism for that, as opposed to creating whatever 
> "context" a
> sidebar has and maintaining it until it explicitly closed down?
> 

I guess this is the main question here. For messaging I think it's very
clear that a specific mechanism works best. For real-time media I'm open
for discussion, but also there I believe that there is a trade-off
between the cost of keeping state just in case vs. the cost of creating
& tearing down state whenever it is really needed.

> Brain
>

Markus
 
> > -----Original Message-----
> > From: xcon-bounces at ietf.org [mailto:xcon-bounces at ietf.org] 
> On Behalf Of
> > Orit Levin
> > Sent: Monday, November 15, 2004 4:53 PM
> > To: xcon at ietf.org
> > Subject: RE: [XCON] Whisper vs. Sidebar
> > 
> > I completely agree with Markus on each of his points.
> > I think we should capture this in the xcon framework.
> > 
> > Orit.
> > 
> > > -----Original Message-----
> > > From: xcon-bounces at ietf.org [mailto:xcon-bounces at ietf.org] On
> > > Behalf Of Markus.Isomaki at nokia.com
> > > Sent: Monday, November 15, 2004 1:10 PM
> > > To: Miguel.An.Garcia at nokia.com; br at brianrosen.net
> > > Cc: xcon at ietf.org
> > > Subject: RE: [XCON] Whisper vs. Sidebar
> > >
> > > Hi,
> > >
> > > I think whether sidebars are public or restricted should be
> > > determined in the conference policy.
> > >
> > > Whispers in general are private, although it might be useful
> > > to have the policy to include a privilege to see a whisper
> > > e.g. for a moderator. But this might be just feature creep.
> > >
> > > Technically I think sidebars and whispers are very different.
> > > Sidebars should be explicitly formed and have a clear
> > > communication context, while whispering should be always
> > > possible and "stateless". The analogy would be the comparison
> > > between delivery of one-shot IMs vs. establishment and
> > > communication within a messaging session.
> > >
> > > Markus
> > >
> > > > -----Original Message-----
> > > > From: xcon-bounces at ietf.org
> > > [mailto:xcon-bounces at ietf.org]On Behalf Of
> > > > ext Miguel Garcia
> > > > Sent: 15 November, 2004 15:56
> > > > To: Brian Rosen
> > > > Cc: xcon at ietf.org
> > > > Subject: Re: [XCON] Whisper vs. Sidebar
> > > >
> > > >
> > > > Well, this is an important subject, because I recently 
> commented (in
> > > > SIPPING) that the conference event package should not show
> > > > participants that are whispering to other participants, due
> > > to privacy
> > > > reasons.
> > > >
> > > > Now you mention that sidebars are also private, something I
> > > thought it
> > > > wasn't the case. So, if sidebars are also private by 
> nature, they
> > > > shouldn't be visible in the conference event package either.
> > > >
> > > > I still think sidebars are public. Participants can 
> freely join a
> > > > sidebar, providing they know how to do it.
> > > >
> > > > - Miguel
> > > >
> > > > Brian Rosen wrote:
> > > >
> > > > > I think both sidebars and whispers are private.  Only the
> > > > people in them
> > > > > know that they are there.
> > > > >
> > > > > Brian
> > > > >
> > > > >
> > > > >>-----Original Message-----
> > > > >>From: Miguel Garcia [mailto:Miguel.An.Garcia at nokia.com]
> > > > >>Sent: Monday, November 15, 2004 7:26 AM
> > > > >>To: Brian Rosen
> > > > >>Cc: 'Eric Burger'; xcon at ietf.org
> > > > >>Subject: Re: [XCON] Whisper vs. Sidebar
> > > > >>
> > > > >>Brian Rosen wrote:
> > > > >>
> > > > >>
> > > > >>>I claim that the ONLY difference between a classic sidebar
> > > > and a whisper
> > > > >>
> > > > >>is
> > > > >>
> > > > >>>that the Coach has a full duplex connection to the
> > > > sidebar, while the
> > > > >>
> > > > >>Agent
> > > > >>
> > > > >>>only has a half duplex connection.  The Mark is not in the
> > > > sidebar at
> > > > >>
> > > > >>all.
> > > > >>
> > > > >>>As with any sidebar, everyone hears the "main mix".
> > > > >>>
> > > > >>
> > > > >>Another difference is that whispers are typically private
> > > in nature,
> > > > >>whereas sidebars are public. If I am whispering to Brian, I
> > > > don't think
> > > > >>the rest of the conference would like to know that I 
> am actually
> > > > >>whispering to Brian. If I want to make this information
> > > > public, I would
> > > > >>use a sidebar.
> > > > >>
> > > > >>- Miguel
> > > > >>
> > > > >>--
> > > > >>Miguel A. Garcia           tel:+358-50-4804586
> > > > >>Nokia Research Center      Helsinki, Finland
> > > > >>
> > > > >
> > > > >
> > > > >
> > > > >
> > > >
> > > > --
> > > > Miguel A. Garcia           tel:+358-50-4804586
> > > > Nokia Research Center      Helsinki, Finland
> > > >
> > > > _______________________________________________
> > > > XCON mailing list
> > > > XCON at ietf.org
> > > > https://www1.ietf.org/mailman/listinfo/xcon
> > > >
> > >
> > > _______________________________________________
> > > XCON mailing list
> > > XCON at ietf.org
> > > https://www1.ietf.org/mailman/listinfo/xcon
> > >
> > 
> > _______________________________________________
> > XCON mailing list
> > XCON at ietf.org
> > https://www1.ietf.org/mailman/listinfo/xcon
> > 
> 
> 
> 
> 
> _______________________________________________
> XCON mailing list
> XCON at ietf.org
> https://www1.ietf.org/mailman/listinfo/xcon
> 

_______________________________________________
XCON mailing list
XCON at ietf.org
https://www1.ietf.org/mailman/listinfo/xcon



_______________________________________________
XCON mailing list
XCON at ietf.org
https://www1.ietf.org/mailman/listinfo/xcon