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

2-3
Design Considerations
Overview
Overview
As described in the previous chapter, an HP Survivable Branch Communica-
tion zl Module (SBM) powered by Microsoft Lync
TM
fits within your current
Lync solution to provide resilient Lync services for a branch office.
This chapter gives you guidelines for planning your solution to meet your
business requirements in several areas:
■ Call capacity
■ Audio quality
■ High availability
■ Ease of management
■ Security policies
Table 2-1. Design Checklist
Task Design Considerations Reference
Plan and purchase Telephony Cards to meet
your call load requirements.
“Considerations for Local PSTN Calls and
Planning Your Telephony Cards” on page 2-5
Estimate wide area network (WAN) bandwidth
requirements and provision the WAN
connection appropriately.
“Considerations for Remote
Communications and Planning Your WAN
Link” on page 2-11
Plan your Media Bypass solution.
“Media Bypass” on page 2-17
Plan Quality of Service (QoS) for voice traffic
within the local area network (LAN).
“Ensuring QoS in the LAN” on page 2-22
Set up QoS for voice traffic over the WAN
connection.
“Ensure QoS for VoIP calls over the WAN”
on page 2-27
Consider other audio quality considerations
such as echo cancellation.
“Ensure Audio Quality on the PSTN
Connection” on page 2-28
Set the appropriate expectations for the
communications available during a WAN
outage.
“High Availability Features” on page 2-29
Provide local DNS services for the SBM in case
of WAN failure.
“DNS Requirements” on page 2-32
Plan backup routes and registrars for branch
users in case the SBM fails.
Set up the SBM as a backup for other sites.
“Lync Guidelines for a Survivable Branch
Appliance” on page 2-31