Cisco TelePresence Administrator's Guide

n Where presence information is provided by the PUA and two or more other sources, the Presence Server
will aggregate the presence information from all presentities to give the "highest interest" information, e.g.
online rather than offline, and in call rather than away.
n If no information is being published about an endpoint, either by the endpoint itself or by the PUA, the
endpoint’s status will be offline. If the PUA is enabled, the offline status indicates that the endpoint is not
currently registered.
FindMe presence
When the Presentity Manager receives a request for information about the presences of a FindMe alias, it
looks up the presence information for each endpoint that makes up that FindMe alias. It then aggregates this
information as follows:
n If the FindMe alias is set to Individual mode, if any one of the endpoints making up that FindMe is in a call
the FindMe presentity’s status will be reported as in call.
n If the FindMe alias is set to Group mode, if any one of the endpoints is online (i.e. not in call or offline) then
the FindMe presentity’s status will be reported as online.
Registration refresh period
The PUA will update and publish presence information on receipt of:
n a registration request (for new registrations)
n a registration refresh (for existing registrations)
n a deregistration request
n call setup and cleardown information
For non-traversal H.323 registrations the default registration refresh period is 30 minutes. This means that
when the PUA is enabled on a VCS with existing registrations, it may take up to 30 minutes before an H.323
registration refresh is received and available presence information is published for that endpoint.
It also means that if an H.323 endpoint becomes unavailable without sending a deregistration message, it
may take up to 30 minutes for its status to change to offline. To ensure more timely publication of presence
information for H.323 endpoints, you should decrease the H.323 registration refresh period (using
Configuration > Protocols > H.323 > Gatekeeper > Time to live).
The default registration refresh period for SIP is 60 seconds, so it will take no more than a minute for the PUA
to publish updated presence information on behalf of any SIP endpoints.
Configuring Presence
The Presence page (Applications > Presence) allows you to enable and configure Presence services on
the VCS.
These services can be enabled and disabled separately from each other, depending on the nature of your
deployment. Both are disabled by default.
Note that SIP mode must be enabled for the Presence services to function.
Presence User Agent (PUA)
The PUA provides presence information on behalf of registered endpoints.
Cisco VCS Administrator Guide (X8.1.1) Page 240 of 507
Applications
Presence

Cisco TelePresence Specifications

General

Brand	Cisco
Model	TelePresence
Category	Server
Language	English