Specifications

12 Reference Architecture | Dell
TM
Unified Communication Solution with Microsoft® Lync® Server 2013 for Single Site
Implementation | Version 1.0
As expected, to support these crucial Lync Server componets, sufficient computing and storage
resouce should be allocated to fulfill the demand from the targeted number of users. The design
should incorporate high availability to ensure minimal service downtime. Therefore, multiple
instances of those important server roles are utilized to avoid a single point of failure.
• Lync Server Edge Architecture: Edge Servers and the Reverse Proxy Servers are located at the
perimeter network. They support the communications across the organization’s firewall between
internal users and various types of external users, such as customers, partners and offsite
employees. For example, internal users can use IM and presence to commuciate with external
users, and they can participate in audio-video and web conferencing with remote employees.
• Enterprise Voice Connectivity: Besides the Voice over IP (VoIP) components at the Standard
Edition servers and signaling and media translation by the Mediation Servers, there are other PSTN
connectivity components required to implement the Enterprise Voice features. This portion covers
those components, such as PSTN gateways, PBX and SBC, and how they connect to the Lync
Server core architecture.
• End User Connectivity: End users connect with Lync services via different types of end-point
devices. This reference architecture describes their connectivity options and highlights how Dell™
Networking W-series switches enhances the user experience of wireless-connected Lync clients.
The physical configuration and design criteria of each major portion will be addressed in the subsequent
sections of this reference architecture guide. The guide will first discuss the design considerations of the
overall reference architecture in Section 3.1 .
Note that Active Directory architecture, firewall and security configuration and data center networking
are outside the scope of this reference architecture. Dell Services can help design a solution for each
individual customer-specific environment.
3.1 Design Considerations
The key design considerations that guided the reference architecture presented in the preceding sections
include:
• High availability
• Application performance
• Resource consolidation
3.1.1 High Availability
The first design consideration is high availability (HA). High availability is a feature that must be considered
at every layer to ensure minimal application downtime. Lync is a critical communication workload at any
enterprise and should it be the only communication end-point for end users, high availability should be
treated as being mandatory. There are two layers of high availability that were considered in the reference
architecture: