[jdev] Gaim and gnomemeeting using jabber

Richard Dobson richard at dobson-i.net
Wed Dec 1 03:59:56 CST 2004

> You don't need to know the SIP uri to know that a client has one.

Exactly this is my whole point here, this guy seems to want to use a 
voip-uri sent as a presence extension to indicate that he is in a call, as 
others have already pointed out as well as me presence is not the correct 
place for this, there is also the point that I was trying to make that why 
do you even need the uri there in the first place, as you point out you dont 
need the voip-uri to know the user is in a call so why even use it for this 

> You only  need to advertise that you have one.


> If you want to receive SIP calls  enable it, if you don't disable it. Or 
> as JEP-115 puts it "Some clients  will have bundles of functionality that 
> can be enabled and disabled."  Doesn't sound very against the spirit of 
> JEP-115.

What I would concider against the spirit of it would be to try to use it to 
publish the voip-uri or your voip presence, rather than as you point out use 
it to advertise the capability.

> Once you want to intitiate your SIP conversation you retrieve the URI. The 
> mechanism for this, well that will depend on your requirments. You could 
> define a simple IQ request for an x:oob packet (this should appeal to you 
> if you think security is important, since you could send an error if you 
> don't want to share).

Good thats exactly the sort of thing I would want it to be.

> But an argument could be made for putting it in  disco or vcard-temp, 
> since that would enable offline retrival.

Yup, I also wasnt quite sure how you would advertise the voip-uri using 
disco because I thought it was supposed to be for advertising capabilities, 
but anyway neither will work because they do not get dynamically updated 
(i.e. resent to people when something changes), so they are useless for 
expressing voip presence.

> What's the case for pubsub anyway? It's not dynamic..

Urm yes it is dynamic, i.e. when you update it it is resent to the people 
who want to know about it.

> in fact, I don't  even *want* the uri to be updated, *unless* I put in a 
> call.

As pointed out above you wouldnt even want it to be a uri, you would want it 
to be something more generic to represent the voip presence i.e. "incall" or 

> Such a  message would be just as much "polluting" to the network as 
> putting your  SIP uri in the presence.

No it wouldnt as using pubsub only the people who wanted to know about it 
would be send the info (so its specifically not polluting the network), but 
using a presence extension everyone would get it regardless of wether they 
wanted it which is "polluting" the network.

> The only thing I can imagine you want this  dynamic is "I have it" or "I 
> don't have it".

Pubsub is there so just like presence you can use it to alert people (just 
the people who actually want to know about it) that you are in calls or not, 
as this person seemed to want to do, from his previous emails he seemed to 
want to be expressing his voip presence (i.e. wether he is in a call or not) 
completely separately from what his IM presence says, now I could only see 
this being realistically done using pubsub, since as others have pointed out 
a presence extension for this is not the right way, also im not quite sure 
how it could fit in with JEP-115 and still be inline with the spirit of it, 
i.e. expressing the capability of being able to do voip is something quite 
different from expressing that you are in a call or not.

> Ofcourse, this could mean we'll end up in the larger discussion.. is 
> JEP-0115 a good idea or just a presence hack to fix the flaws of Disco 
> like iChat and avatars? Why doesn't this use pubsub other than the well 
> know reasons "there's no good pubsub server out there, no client supports 
> it etc." for example?

No this isnt what I was trying to point out at all, I can see that JEP-115 
being in presence could be seen as bad in some ways but it is a very 
different kettle of fish from expressing your voip presence, client 
capabilities are something that the vast majority of clients are likely to 
be interested in so its not so bad it being in presence as it will be useful 
to most people but voip presence on the other hand I cant see being useful 
to most people, most clients will not care wether you are in a voip call or 
not as they dont do voip, but for the few who do they can subscribe to your 
voip presence via pubsub so they get your voip presence but the people who 
dont want it will not and unnecessary bandwidth will not be wasted, I 
thought this was the whole point of pubsub and it seems a perfect fit 


More information about the JDev mailing list