Unified communications (UC) boosts business productivity by providing an efficient, flexible and effective working experience. It offers real-time communications within organizations and with partners and customers. Providing these services on-premises gives IT greater control over performance and quality of service, which can be enhanced by the right design and building blocks. With this reference architecture, Dell provides an end-to-end UC solution for users at a central site with one or more branch office locations.
The reference architecture provides a high-level design and implementation scenario that includes all workloads for 10,000 Lync users, scalable up to 60,000 Lync users. These workloads include instant messaging, presence, audio-video-Web Conferencing and enterprise voice. Persistent Chat is an optional role which can be deployed based on customer requirements.
As shown in the above figure, this reference architecture is based on the concept of a Pod. A Pod is a standardized configuration of the minimum server and storage resources sized to meet the solution requirements. Initially, this solution starts with two Pods to cater 10,000 Lync users, and can scale up to six Pods to accommodate 60,000 users. The configuration within each Pod in a deployed solution must remain the same as you add Pods to accommodate more users.
This end-to-end solution integrates products optimized for UC from the Dell end-to-end solution portfolio, including Dell PowerEdge Servers, Dell Storage, Dell Networking, Dell IT management software and end-user client devices, along with third-party gateways. Based on the powerful, converged PowerEdge FX2s, the solution delivers high performance in a virtualized environment. Dell Unified Communication Command Suite provides diagnostics and analytics for the Lync environment.
As shown above, the reference architecture depicts a customer scenario that consists of one central site and one or more branch sites with all workloads. For voice connectivity, the site may have either ISDN (T1/PRI) or SIP trunk connections provided by an Internet Telephony Service Provider (ITSP) or Public Switched Telephone Network (PSTN) Provider. In this reference architecture, the Lync infrastructure connects to ITSP via a SIP trunk using a session border controller (SBC).
The primary component of this architecture is a Lync Server 2013 Enterprise Edition server pool with collocated Archiving and Monitoring Sever Components that serve different workloads. To provide for higher quality Enterprise Voice calls, a dedicated Lync Server 2013 Mediation pool is deployed. In addition, a SQL Failover Cluster is used to host the Lync Back End, archiving and monitoring databases. A highly available UC solution is designed to keep in mind a single server failure or entire PowerEdge FX2s chassis level failure without any compromise with performance.
Apart from the Lync primary components, the architecture leverages virtual machines to deploy the Office Web App Server, Edge Server, reverse proxy, load balancer and enterprise voice connectivity using the third-party SBC.
To verify the implementation, the Microsoft Lync Stress and Performance Tool was run with instant messaging, audio conferencing, video conferencing using multi-view, application sharing, and other workloads. The performance of the Lync Front End was verified as being within recommended thresholds. A thorough investigation was conducted using the design framework described in the reference architecture. Design principles, such as high availability, application performance and resource consolidation are verified as part of the study.
A detailed technical paper that describes this implementation is available at http://en.community.dell.com/techcenter/extras/m/white_papers/20441067.