March 2006
Intermediate to advanced
464 pages
12h 16m
English
book
The IMS: IP Multimedia Concepts And Services, Second Edition
by Miikka Poikselka, Georg Mayer, Hisham Khartabil, Aki Niemi
Content preview from The IMS: IP Multimedia Concepts And Services, Second Edition
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.
4.6. Presence service architecture in IMS
A user's presence information can be obtained from a multiplicity of entities in the Internet Protocol Multimedia Subsystem (IMS) network:it could be a PUA located in a foreign network, a PUA at the terminal or a PUA located as an entity in the network. The presence server is an example of an IMS application server. Watchers may be in the same home domain as the presentity or in a foreign domain.
Figure 4.2 represents a reference architecture to support a presence service in the IMS.
Figure 4.2. Reference architecture to support a presence service in IMS.
The entities are defined as follows:
Presence server – manages presence information uploaded by PUAs and handles presence subscription requests.
Watcher presence proxy – identifies the target network for a presentity and resolves its address.
Presentity presence proxy – identifies the presence server assigned to a certain presentity.
PUAs – assemble and provide presence information to the server.
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.
Read now
Unlock full access
More than 5,000 organizations count on O’Reilly
O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.