HP Survivable Branch Communication zl Module powered by Microsoft Lync Planning and Design Guide 2011-02

2-31
Design Considerations
Planning for High Availability
Planning for Failover Situations
The SBM administrator does not need to complete any setup on the SBM to
prepare it for failover situations. The SBM automatically detects when the
WAN connection is down and reroutes communications that would pass over
the WAN connection over the PSTN instead.
Lync Guidelines for a Survivable Branch Appliance
The following configuration is recommended to provide redundancy for Lync
users’ voice services:
■ Configure the SBM as the branch users’ primary registrar.
■ Configure a Lync Front-End Server pool at the central site as the users’
backup registrar. (This configuration is made by default when the SBM is
added as a survivable branch appliance.)
Branch users can place calls to Lync users
at other sites in the enterprise.
X (routed through the
WAN)
X (rerouted through
the PSTN)
Note that calls that
were begun before
the failure will be
dropped and must be
placed again.
Lync users at other sites can place calls to
local branch users.
X (routed through the
WAN)
X (rerouted through
the PSTN)
Lync users can send IMs to Lync users at
other sites in the enterprise (and vice
versa).
X
Lync users can send IMs to users outside
the company.
X
Branch users can see the presence of other
Lync users and their own contact lists.
X
Branch users can participate in conference
calls and use all of Lync’s conferencing
features.
X Limited audio-
conferencing options
are still available in
survivability mode.
Branch users can reach their voice mail. X Voice mail can be re-
routed through the
PSTN.
When branch users set their status to Do
Not Disturb, their calls are routed to their
voice mail.
X
Feature Supported in Normal
Operation
Supported during
WAN Outage