CounterPath Bria Professional 2.5 Configuration Guide - Manual (Page 22)

CounterPath Corporation
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2.15 Presence
This group of settings lets you configure how presence is supported when presence is handled using SIMPLE
on SIP accounts. For presence on XMPP accounts, no special configuration is required: presence subscriptions
are always created for XMPP buddies.
If you are not supporting presence through SIP, make sure you disable presence on every SIP account.
If you are supporting presence through SIP and your users have several SIP accounts, you will typically enable
presence on only one SIP account. Make sure you disable presence on the other SIP accounts.
If you support presence, you should also read “Resources” on page 19 for information on how Bria Professional
stores the presence information (buddy list) and privacy rules.
How Presence Subscriptions are Handled
Bria Professional supports IETF standard SIMPLE presence using a SIP subscription to the presence event
package. Bria Professional supports the SIMPLE rich presence extensions (RPID - RFC 4480), which allows
detailed presence information to be conveyed in a standards-compliant manner.
Peer-to-Peer Presence Mode
In peer-to-peer presence modes, the clients in the network send SIP SUBSCRIBE and NOTIFY messages
directly to one another. The Bria Professional that receives the request consults the local copy of the privacy
rules to determine whether a rule already exists. If no rule exists for the other party, then the request is deferred
to the user through a popup; the user’s action typically results in a privacy rule being created. The amount of
SIP message traffic on the network can be substantially larger than in presence agent mode.
Presence Agent Mode
In presence agent mode, when Bria Professional is first started, it sends presence information to the network
using the SIP PUBLISH mechanism (RFC 3903). Bria Professional still sends a SUBSCRIBE message per
contact found in the contact list when it is first started, but the presence agent will simply return a NOTIFY
message with the current presence document on behalf of the contact that was subscribed to. As well, Bria
Professional subscribes to the presence info (winfo - RFC 3857, 3858) event package which will inform the user
when they have to make a presence authorization decision.