Presence Services (the Presence Server and the Presence User
Agent) are both disabled by default.
These services can be enabled and disabled separately from
each other, depending on the nature of your deployment.
To enable and disable the

Presence Server

and

Presence User

Agent

•

Go to Applications > Presence
You will be taken to the Presence page.

•

xConfiguration Applications Presence

Presence User Agent (PUA)

Enabled

If the PUA is enabled, it will publish presence information for
all locally registered endpoints, whether or not those endpoints
are also publishing their own presence information. Information
published by the PUA will be routed to a Presence Server acting
for the endpoint’s domain. This could be the local Presence
Server, or (if this is disabled) a Presence Server on another
system that is authoritative for that domain.

Disabled

If the PUA is disabled, only those endpoints that support
presence will publish presence information. No information will be
available for endpoints that do not support presence.

Presence Server

Regardless of whether or not the Presence Server is enabled, the
VCS will still continue to receive PUBLISH messages if they are
sent to it from any of the following sources:

•

locally registered endpoints that support presence

•

the local PUA (if enabled)

•

remote SIP Proxies

Enabled

If the local Presence Server is enabled, it will process any
PUBLISH messages intended for the SIP domains for which the

local VCS is authoritative. All other PUBLISH messages will be
proxied on in accordance with the VCS’s SIP routing rules.

SIP routes are configured using the CLI only. See

xConfiguration SIP Routes Route [1..20]

for

details.

Disabled

If the local Presence Server is disabled, the VCS will proxy
on all PUBLISH messages to one or more of its neighbor
zones in accordance with its locally configured

call processing

rules. The local VCS will do this regardless of whether or not
it is authoritative for the presentity’s domain. If one of these
neighbors is authoritative for the domain, and has a Presence
Server enabled, then that neighbor will provide presence
information for the presentity.

Recommendations

VCS Expressway and VCS Control

The recommended configuration for a VCS Expressway when
acting as a traversal server for a VCS Control is to enable the PUA
and disable the Presence Server on the VCS Expressway, and
enable the Presence Server on the VCS Control. This will ensure
that all PUBLISH messages generated by the PUA are routed to
the VCS Control.

VCS neighbors

We recommend that if you have a deployment with two or more
VCSs neighbored together, you enable the presence server on
just one VCS. This will ensure a central source of information for
all presentities in your network.

VCS clusters

For information about how Presence works within a VCS cluster,
see the

Clustering and Presence

section.

Note that any defined

transforms

also apply to any

Publication, Subscription or Notify URIs handled by the
Presence Services.

Presence Server expiration times

Subscription expiration time

This is the maximum time (in seconds) within which a subscriber
must refresh its subscription. If the subscriber does not send a
refresh within this period, the Presence Server will stop sending
NOTIFY messages to it.
You may wish to increase this value in deployments with large
numbers of endpoints, to prevent too many messages being sent
over your network.

Publication expiration time

This is the maximum time (in seconds) within which a publisher
must refresh its publication. If the publisher does not send a
refresh within this period, the Presence Server will show its
presence as Offline.
You may wish to increase this value in deployments with large
numbers of endpoints, to prevent too many messages being sent
over your network.