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

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Design Considerations
Planning for High Availability
Figure 2-7. Port Numbers on Telephony Cards
Planning for High Availability
The SBM is a survivable solution. This section describes the module’s high-
availability features and its behavior during various failover situations. It also
explains how you must deploy the module to ensure that it meets your
requirements for high availability.
High Availability Features
The SBM has several links that can provide redundancy for each other. It uses
the branch office’s WAN link to the main office and has PSTN connections of
its own. If the WAN link fails, the SBM can route calls that typically traverse
the WAN through its local PSTN connection, preserving all voice services for
branch users. Conversely, if the SBM’s PSTN connection fails, it can route
users’ PSTN calls through the WAN connection to PSTN gateways at other
sites. In the rare case that the SBM itself fails, users can direct all calls over
the WAN link to the central site Lync servers.
However, the SBM has features that minimize the chance of failure. For
example, the HP zl switch in which the SBM is installed, which provides the
SBM with power and connectivity to the rest of the LAN, can deliver several
high-availability features.
To enable high availability through an HP E8200 zl Series switch, you can
install:
■ Redundant management modules
■ Redundant fabric modules
■ Redundant power supplies
Port 1
Port 1