Subject: [MEDIACTRL] Reservation of conference speaker slots

From: "Rusu Andreea-B00553" <[email-masked]>
Date: Fri, 6 Nov 2009 14:08:12 -0000

Hi,
 
I have two questions related to the mixer package.
 
Question 1: If a conference is created with a number N of reserved
listeners and talkers and AS tries to join N+1 users to the conference,
should MS return a conference full error for the N+1 join command? The
phrase "reserved-talkers/reserved-listeners indicate the requested
number of guaranteed speaker slots to be reserved for a conference" does
not necessarily imply that reserved-talkers plus reserved listeners
represent the maximum number of allowed participants.
 
Question 2: As it is stated in the mixer draft when a conference is
created the MS must guarantee the number of speaker slots from a
conference. When an INVITE is received by the MS from the AS with the
media settings of a User, MS creates a media connection (channel) which
is used for services like DTMF detection, voice recording etc. A media
connection is a different resource than a mixer speaker slot. Even if
the MS guarantees the mixer speaker slots, the MS may reject the User
INIVITEs due to lack of resources for opening media connections. Is this
a valid scenario from MediaCtrl point of view?

Thank you in advance,

Andreea Rusu

---

From: Lorenzo Miniero <[email-masked]>
Date: Sat, 7 Nov 2009 11:23:27 +0100

Hi Andreea,

I'm not one of the authors of the draft but I'll give you my
interpretation of these issues, since we implemented the package too.

About question 1, I think it really depends on the direction you're
going to join a new participant with. If you have 5 reserved-talkers,
with all the seats taken, and you're adding a participant with a
sendonly/sendrecv direction, you're getting the 410; you're still free
to add the user as a passive participant (recvonly), as long as you're
not crossing the reserved-listeners as well. The same would happen for
a modify-join.

About question 2, my guess is that it definitely is a valid scenario.
The mixer package only gets invoked after a media session has been
accepted/created, and so it is at a different, higher, level. As you
say, a mixer speaker slot may be something different from the generic
media connection resource, and so allocating one may fail for different
reasons.

Hope that helped,
Lorenzo

On Fri, 6 Nov 2009 14:08:12 -0000

-- 
Lorenzo Miniero <[email-masked]>

---

From: "Rusu Andreea-B00553" <[email-masked]>
Date: Mon, 9 Nov 2009 09:45:39 -0000

Hi Lorenzo,

Thanks for the reply.

Regarding question 1, I think it should be clarified in the mixer draft
that the number of reserved-talkers represent the maximum number of
possible talkers in a conference. The syntax "media server guarantees
the number of speaker slots" leaves room for interpretations. One could
understand that the reserved-talkers represent the minimum number of
possible talkers in a conference.
I guess that if MS wants to add an extra participant to the conference
it would have to issue a modifyconference first with a bigger number for
reserved-talkers/reserved-listeners.

Regarding question 2, I was thinking that the MS should reply with a 503
Service Unavailable to an INVITE request in case it has no more
resources for opening media connections (it is overloaded). What do you
think?

Have you thought about adding more fail scenarios in the drafts with
call flows?

Thanks,
Andreea Rusu

-----Original Message-----
From: Lorenzo Miniero [mailto:[email-masked]] 
Sent: Saturday, November 07, 2009 12:23 PM
To: Rusu Andreea-B00553
Cc: [email-masked]
Subject: Re: [MEDIACTRL] Reservation of conference speaker slots

Hi Andreea,

not crossing the reserved-listeners as well. The same would happen for a
modify-join.

Hope that helped,
Lorenzo

On Fri, 6 Nov 2009 14:08:12 -0000
"Rusu Andreea-B00553" <[email-masked]> wrote:

> listeners and talkers and AS tries to join N+1 users to the 
> conference, should MS return a conference full error for the N+1 join 
> command? The phrase "reserved-talkers/reserved-listeners indicate the 
> requested number of guaranteed speaker slots to be reserved for a 
> conference" does not necessarily imply that reserved-talkers plus 
> reserved listeners represent the maximum number of allowed
participants.
> media settings of a User, MS creates a media connection (channel) 
> which is used for services like DTMF detection, voice recording etc. A

> media connection is a different resource than a mixer speaker slot. 
> Even if the MS guarantees the mixer speaker slots, the MS may reject 
> the User INIVITEs due to lack of resources for opening media 
> connections. Is this a valid scenario from MediaCtrl point of view?
>  
>  
> Thank you in advance,
> 
> Andreea Rusu
> 
>  
>