[SIPForum-discussion] Basic questions about Presence Event Package (RFC 3856)

[Rodrigo Pimenta Carvalho]

Hi.

 

I had redden the IETF RFC 3263 (Locating SIP Servers), the RFC 3680 (Event
Package for Registrations) and the RFC 3856 (Presence Event Package)

 

Now, I have some questions. Any hint about the following questions will help
me a lot.

 

1)      The FRC 3856 says that a watcher can subscribe to a kind of server,
to get information about the presence of some user. The presence of the user
is updated with the PUA action, like following shown.

 

 

   Watcher             Server                 PUA (Presence User Agent)
      | F1 SUBSCRIBE      |                    |
      |------------------>|                    |
      | F2 200 OK         |                    |
      |<------------------|                    |
      | F3 NOTIFY         |                    |
      |<------------------|                    |
      | F4 200 OK         |                    |
      |------------------>|                    |
      |                   |                    |
      |                   |   Update presence  |
      |                   |<------------------ |
      |                   |                    |
      | F5 NOTIFY         |                    |
      |<------------------|                    |
      | F6 200 OK         |                    |
      |------------------>|                    |
 
 
      If the user turns off your device (Ex: turning off his SIP Phone), the
PUA will update the user's presence with the Server. Then, the watcher can
know the user is no more present in some device. However, if the same user
turns on another device, but in some place completely out off the PUA/Server
domain, how can the Server be updated correctly?

 

2)      Where the Server must be running? 

3)      How many PUA does exist for a user?

4)      How many Servers do exist for a user?

5)      Where the PUAs must be running?

6)      Does a SIP Phone have a PUA? If yes, how can it know where is the
Server? If not, is it possible putting a PUA inside of a SIP Phone?

7)      How can the watcher and the user(PUA)  know that they are using a
same Server?

8)      If the Server is a service, who should serve it? A private company?
A public one? 

 

 

Thanks.

 

Rodrigo Pimenta Carvalho.

Brazil.

 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://sipforum.org/pipermail/discussion/attachments/20060710/5757b161/attachment-0003.html>