Part 3
How SIP Transforms User
Communications
In This Part
ᮣ Getting familiar with presence-enabled communications
ᮣ Routing communications with presence
ᮣ Choosing your modes of communication freely
ᮣ Recognizing benefits for the mobile user
T
his part describes in detail how SIP, presence, and user
preference can enhance the productivity and quality
of communications and explains the concept of user-centric
communications.
To Be Available or Not to Be
Available . . . Presence-Enabled
Communications
When a user activates his or her communications device
(user agent, or UA), it registers its presence on the network,
indicating its ability to communicate. Presence distributes
the following information:
ߜ User status (that is, online or offline)
ߜ User availability (such as available, busy, on the phone,
or out to lunch)
ߜ User’s desired contact means (such as instant messag-
ing, desk phone, cell phone, pager, and so on)
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