[Standards-JIG] media conferencing, flow segmenting

CORVOYSIER David FTRD/DMI/REN david.corvoysier at francetelecom.com
Mon Mar 15 14:27:39 UTC 2004


OK, now I understand the quotas thing ... 

Here are some ideas for the disruptive case you mentioned ...

Note first that for a given conference there might be several
"disruptive" server behaviors:
- the quota applies only to the conference creator (conference is closed
when the owner has exceeded his quota),
- each participant has a quota (only those who have exceeded their quota
are kicked),
- there is a quota per conference (conference is closed when the quota
has exceeded).

Anyway, for any of these mechanisms, I think you can use the MUC
protocol:

-> you can provide a reason in the presence unavailable stanza that is
sent when kicking someone or when destroying a conference

<presence
    from='harfleur at henryv.shakespeare.lit/pistol'
    to='pistol at shakespeare.lit/harfleur'
    type='unavailable'>
  <x xmlns='http://jabber.org/protocol/muc#user'>
    <item affiliation='none' role='none'>
      <actor jid='fluellen at shakespeare.lit'/>
      <reason>You have exceeded your quota</reason>
    </item>
    <status code='307'/>
  </x>
</presence>

-> you can always reject conference creation by sending a presence type
error with appropriate code and optionnal text

<presence
    from='darkcave at macbeth.shakespeare.lit/thirdwitch'
    to='hag66 at shakespeare.lit/pda'
    type='error'>
  <error code='405' type='cancel'>
    <not-allowed
        xmlns='urn:ietf:params:xml:ns:xmpp-stanzas'/>
	<text xmlns='urn:ietf:params:xml:ns:xmpp-stanzas'>You have
exceeded your quota</text>
  </error>
</presence>

-> similarly, you can prevent someone from entering a conference and
specify a text in the error

<presence
    from='darkcave at macbeth.shakespeare.lit'
    to='hag66 at shakespeare.lit/pda'
    type='error'>
  <error code='403' type='auth'>
    <forbidden
        xmlns='urn:ietf:params:xml:ns:xmpp-stanzas'/>
	<text xmlns='urn:ietf:params:xml:ns:xmpp-stanzas'>You have
exceeded your quota</text>
  </error>
</presence>

Of course, these are only suggestions (especially the error codes: I
would have preferred something more consistent, ie the same code for all
cases).

For the notification case, we would need something like a presence
type="warning" (augh! Ugly ! ... it may sound terrible to stpeter ;-) ),
or just a message with a special warning tag embedded ...
I don't know if such a concept already exists in Jabber ...

<message
    from='darkcave at macbeth.shakespeare.lit'
    to='hag66 at shakespeare.lit/pda' id='first_reminder'>
  <warning xmlns='http://jabber.org/protocol/mmuc#warning'>
    <quota-exceeded/>
    <text xmlns='urn:ietf:params:xml:ns:xmpp-stanzas'>You have exceeded
your quota</text>
  </warning>
</presence>

This could be used for other kind of warnings: 
- your connection generates too many errors,
- your latency time is too high (is it relevant for multimedia ?),
- you use a deprecated encoding scheme,
- server restart in x minutes

Again, these are only ideas ...

Sorry for the long post.

David




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