Microsoft Lync Server 2013 does a commendable job building on the features introduced in Lync Server 2010, making the transition to this new version compelling for IT managers and unified communications (UC) implementers. Like its predecessor, Lync Server 2013 provides support for enterprise IM, presence, and conferencing, with direct integration to the Microsoft Office suite of applications. (In case you're unfamiliar with Lync, presence is a feature that displays a user's availability, willingness to communicate, and contact information.)

There are several significant architectural changes that simplify the deployment of Lync Server 2013, with one of the biggest being server role consolidation. I'll discuss the server role changes as well as other changes to Lync Server 2013's topology. I'll also discuss other noteworthy enhancements made to the:

  • Role-based access control (RBAC) feature
  • Disaster recovery, high availability, and archiving features
  • Edge Server services
  • IM and presence features
  • Conferencing features
  • VoIP functionality, which is called Enterprise Voice
  • Lync 2013 client

Lync Topology Changes

The Lync topology is the overall layout of the Lync environment, including Front End Servers, Edge Servers, and Mediation Servers. The Lync topology consists of multiple server roles that work together to provide IM, presence, conferencing, and VoIP functionality. The topology changes in Lync Server 2013 bring about many rich enhancements that will affect how administrators design and ultimately deploy their Lync environments and approach upgrades.

Figure 1: Changes in the Architecture

One of the most important topology changes deals with the Front End pools. In Lync Server 2013 Enterprise Edition, the architecture of the Front End pools has been changed to provide a more distributed systems architecture, as Figure 1 shows.

In the Lync Server 2013 architecture, the back-end Microsoft SQL Server database is no longer the point of reference for the real-time data store in the Lync pool that contains the updated presence information, permissions, and user contacts. Those responsibilities have been transferred to the Lync 2013 Front End Servers. This distribution of data storage improves performance because the Back End Server no longer has to render the up-to-the-second transactions for users regarding presence, contacts, and conferencing information. It also provides scalability within the pool and eliminates the single point of failure (i.e., the single Back End Server).

There are many changes to the server roles in Lync Server 2013. Here are the most important changes:

  • Lync Server 2013 no longer has a separate Archiving Server role. Archiving is an optional feature available on all Front End Servers.
  • Lync Server 2013 no longer has a separate Monitoring Server role. Monitoring is an optional feature available on all Front End Servers.
  • The A/V Conferencing Server role is now part of the Front End Server role.
  • The Persistent Chat Server is a new server role. (Persistent Chat is the new name for Group Chat. Persistent Chat will be discussed in more detail in the "Lync 2013 Client Enhancements" section.)
  • The Director role is no longer presented as a recommended role but rather an optional role. Organizations that have specific security requirements for allowing external traffic through the perimeter network to the Lync servers inside the network might consider deploying this role.

RBAC Enhancements

In Lync Server 2013, Microsoft enhanced the RBAC feature in two major ways. First, there are two new predefined roles: Response Group Manager and Persistent Chat Manager. Members of the Response Group Manager role can manage specific Response Group queues. Members of the Persistent Chat Manager role can manage specific Persistent Chat rooms.

The second enhancement is the ability to create custom roles. You can create custom roles that have privileges to run a specified set of Windows PowerShell cmdlets or specified PowerShell scripts in the Lync Server Management Shell.

Disaster Recovery, High Availability, and Archiving Changes

As in Lync Server 2010, Lync Server 2013's main high availability approach is based on server redundancy through pooling. If a server running a certain server role fails, the other servers in the pool running the same role will take the load of that server. This applies to Front End Servers, Edge Servers, Mediation Servers, and Directors.

Lync Server 2013 adds new disaster recovery measures by enabling you to pair Front End pools together. The two pools can be in the same geographic location or different geographic locations. If one of the Front End paired pools goes down, an administrator can manually fail over the users from the primary pool to the backup pool to provide continuation of service.

Lync Server 2013 also adds Back End Server high availability. This is an optional topology in which you deploy two Back End Servers for a Front End pool and set upsynchronous SQL Server database mirroring for all the Lync databases running on the Back End Servers. You can also deploy a witness for the mirror.

Enabling the Archiving feature in a Lync 2013 pool provides new capabilities that improve deployment and operation efficiency, including:

  • Microsoft Exchange Server 2013 integration. The deprecation of the Microsoft Messaging Queuing Service and the usage of the Lync Storage service in Lync Server 2013 mean that you can use a unified archiving storage architecture if your environment is running Exchange 2013 and Lync Server 2013. When you enable the Archiving feature, you can integrate data storage for Archiving with your existing Exchange 2013 storage for all users who are homed on Exchange 2013 and have their mailboxes put on In-Place Hold. With this new archiving environment, you don't need to deploy separate SQL Server databases to archive Lync data. In addition, you can search and retrieve data from a single database instead of multiple databases when searching for user information for compliance situations.
  • SQL Server database mirroring. When you deploy the Archiving feature, you can enable SQL Server database mirroring for your archiving database. This gives you more flexibility if you need to provide high availability across data centers.
  • Archiving of whiteboards and polls. Archived conference content now includes whiteboards and polls that are shared during the meeting.

Changes to the Edge Server Services

Lync Server 2013 introduces changes to better integrate and extend the existing Edge Server services that are available to organizations. The following is a high-level overview of the changes that can affect the planning and deployment of Edge Server services.

Support for IPv6 addressing. Lync Server 2013 supports IPv6 addressing for all Edge Server services.

Extensible Messaging and Presence Protocol (XMPP) proxy and gateway. Lync Server 2013 introduces a fully integrated XMPP proxy (which you deploy on Edge Servers) and XMPP gateway (which you deploy on Front End Servers). You can deploy XMPP federation as an optional component. Once deployed and configured in the organization, you can create and configure policies that support XMPP federated domains. Optionally, you can configure relationships with each XMPP federated partner to allow users to place contacts from specific organizations in their contacts list. Doing this can strengthen security.

Mobility services for mobile clients. Mobility services enable supported Lync mobile clients to perform such activities as sending and receiving IM messages, viewing contacts, and viewing presence information right out of the box. In addition, mobile devices support some Enterprise Voice features, such as clicking once to join a conference, single number reach, voicemail, missed call notification, and making and receiving calls on a mobile phone using a work phone number instead of the mobile phone number (i.e., the Call via Work option).

IM and Presence Enhancements

Lync Server 2013 has new IM and presence features. If your organization runs Exchange 2013, users can take advantage of a unified contact store. Users can manage their contacts in Outlook 2013, Outlook Web App (OWA), and the Lync client. In addition, the new XMPP integration feature lets Lync users exchange IM messages and presence information with Google Talk users and users of other public IM providers that utilize XMPP.

Conferencing Enhancements

Lync Server 2013 introduces many new and updated features that enhance conferencing. The updated Join launcher now validates each meeting before launching a client. It supports opening a meeting in the following clients:

  • Windows 8
  • Microsoft Internet Explorer (IE) 10
  • Windows Phone 7
  • Google Android devices
  • Apple iOS devices

Lync Server 2013 supports HD video. Users can experience resolutions up to HD 1080P in two-party calls and multiparty conferences. The H.264 video codec is the default for encoding video on Lync 2013 clients. It supports a greater range of resolutions and frame rates, and improves video scalability. It also allows a more adaptive approach for the Lync infrastructure to render and mix HD resolution to clients.

After users connect to a conference, they can see everyone in the Gallery View. If a video isn't available for a participant, the person's Lync profile picture will appear, as Figure 2 shows.

Figure 2: Gallery View After a User Connects to a Conference

To see the participants' names, users can hover the mouse over the View Participants button or click Show Participant List.

In video conferences with two to four people, users will see the videos of all the participants in the Gallery View (assuming everyone has a video feed). If the conference has more than five participants, videos of only the most active participants appear in the top row and photos appear for the other participants. Presenters can use the video spotlight feature to select one person's video feed so that every participant in the meeting sees only that participant.

Many other enhancements have been made to improve the users' experience during conferencing, including:

  • Video is enhanced with face detection and smart framing, so that a participant's video moves to help keep them centered in the frame.
  • Easy-to-use audio controls in the meeting room enable users to control audio options, such as mute, unmute, and change device.
  • With split audio and video streams, participants can add their video feed to a conference but dial in to hear the meeting if they just want to participant through audio only or want leverage their Public Switched Telephone Network (PSTN) device.
  • When sharing programs, users can select multiple programs to share if they need to work with more than one program.
  • Users can switch between content types using the Share content and lead meeting activities option. Users can also use the Meeting Content menu to choose which content they want to share.
  • Users can merge another open conversation into the meeting by using the Merge This Call Into option on the More Options menu.
  • Meeting recordings are automatically saved in a format (e.g., MP4) that plays in Windows Media Player (WMP). Users can easily share the file with anyone or use the Publish feature in Recording Manager to post the recording on a shared location.

Lync Server 2013 now uses Office Web Apps and Office Web Apps Server to handle PowerPoint presentations shared during a conference. In Lync Server 2010, presentations were shared remotely with the Lync Web App. Using Office Web Apps Server provides higher-resolution displays, better support for PowerPoint capabilities, and access to more types of mobile devices. It also gives users (who have the appropriate privileges) the ability to scroll through a PowerPoint presentation independent of the presentation itself. For more information about Office Web Apps Server, see "Lync Server 2013: Introduction to Office Web Apps Server."

Any document that's shared during a conference is archived in Exchange 2013 data storage if Exchange integration is enabled with the Archiving feature. This includes PowerPoint presentations, attachments, whiteboards, and polls.

Changes to Enterprise Voice

To enhance Enterprise Voice, Microsoft added and enhanced several routing features. Lync Server 2013 supports multiple trunks between Mediation Servers and gateways. A trunk is a logical association between a port number and Mediation Server with a port number and gateway. This means a Mediation Server can have multiple trunks to different gateways, and a gateway can have multiple trunks to different Mediation Servers. Intertrunk routing makes it possible for Lync Server 2013 to interconnect an IP PBX system to a PSTN gateway or interconnect multiple IP PBX systems. Lync Server 2013 serves as the glue (i.e., the interconnection) between different telephony systems.

Figure 3 illustrates the evolution of Mediation Server integration with third-party PSTN gateways.

Figure 3: Evolution of Mediation Server Integration with Third-Party PSTN Gateways

Microsoft Office Communications Server (OCS) 2007, which is the predecessor to Lync Server 2010, provides a one-to-one (1:1) relationship between a single Mediation Server and a single gateway. Lync Server 2010 provides a one-to-many (1:M) relationship between a single Mediation Server and one or more gateways. Lync Server 2013 provides a many-to-many (M:N) relationship, where multiple Mediation Servers can connect to many gateways. Having multiple Mediation Servers communicate with multiple gateways increases the resiliency for inbound and outbound call routing. Mediation Server routing also makes reliability and disaster recovery planning easier.

Lync Server 2013 also introduces new enhancements to voice routing, such as:

  • Enhanced call authorization for call forwarding and simultaneous ringing
  • Manager/delegate simultaneous ringing
  • Voicemail escape (provides a method for managing voicemails when users are set up for simultaneous ringing on multiple phones)
  • Caller ID presentation (provides the administrator the ability to modify the format of the calling party's phone number)
  • Conference dial-out for users not enabled for Enterprise Voice

Lync 2013 Client Enhancements

Both administrators and users will appreciate the enhancements in the Lync 2013 client. The most noteworthy changes are the client's integration with Office 2013 setup, new administrative templates, virtual desktop infrastructure (VDI) support, Persistent Chat, and a redesigned conversation window. There are also updates to the Lync Web App, the web-based conferencing client for participants outside of an organization.

Integration with Office 2013 setup. The Lync 2013 client and the Online Meeting Add-in for Lync 2013 (which supports meeting management from within the Outlook messaging and collaboration client) are both included with the Office 2013 Setup program. With the previous versions of Lync, you had to use the Windows Installer properties to customize and control the Office installation.

New administrative templates. Microsoft recommends that you use the Lync Server Management Shell, which utilizes PowerShell, to enforce policies on Lync 2013 clients. However, for certain situations in which the client settings need to take effect before the user actually logs on to Lync, there are a handful of Lync 2013 Group Policy settings that can be applied. The method for deploying Lync Group Policy settings has changed. In the previous versions of Lync, you need to use the Communicator.adm file to define Group Policy settings. In Lync 2013, you can use the Lync .admx and .adml administrative templates, which are part of the Office Group Policy Administrative Templates.

VDI support. The Lync 2013 client now supports audio and video in a VDI environment. After users connect a video or audio device to their computers, they can connect to the virtual machine (VM), log on to the Lync 2013 client that's running on the VM, and participate in real-time audio and video communication.

Persistent Chat. The Lync 2013 client integrates the features previously provided by Lync 2010 Group Chat. In other words, a separate Group Chat client is no longer required. In addition, Microsoft changed the name from Group Chat to Persistent Chat. With this single client, users can jump right into a chat room using a UI like that shown in Figure 4.

Figure 4: Persistent Chat Functionality in the Lync 2013 Client

This single client will also make your job easier because you don't have to deploy and manage multiple clients.

Lync Server 2013 has simplified the administration of Persistent Chat by including an administrative UI that's integrated with the Lync Server Control Panel. Also, the Persistent Chat Server includes a collection of PowerShell cmdlets to create and manage Persistent Chat Server categories, rooms (including deleting rooms), and add-ins. You need to be a member of the new CsPersistentChatAdministrator role in order to create and manage chat rooms using the PowerShell cmdlets or Lync Server Control Panel. For more information about Persistent Chat, see "Lync Server 2013 Persistent Chat."

Redesigned conversation window. The conversation window in the Lync 2013 client has been redesigned to provide quicker access to features. Tabbed conversations are now built into the Lync 2013 client, as shown in Figure 5.

Figure 5: New Tabbed Conversations Feature in the Lync 2013 Client

With the new tabbed conversations feature, users can keep all their calls, IM messages, and chat rooms in one conversation window. The tabs along the left side of the conversation window let users navigate easily among all active conversations. Other changes include the following:

  • With the click of the pop-out button, users can move an individual conversation into a separate window, which they can resize.
  • The Lync 2013 client remembers a user's conversation state, even when the user logs out and logs back on to Lync.
  • Users can quickly add IM, video, program sharing, desktop sharing, or web conferencing tools to any conversation by clicking buttons in the conversation window.
  • In a meeting where video or content is being shared, users can click the undock button to move the shared video or content into a separate window, which they can resize.

Lync Web App updates. Lync Web App now allows users of Windows or Apple Macintosh PCs to join Lync meetings from within their browser and experience the same features as they would on a regular on-premises Lync client. No local client installation is required to use Lync Web App. In addition, there's no longer a requirement to install Silverlight on the desktop of the user who is participating through the browser. However, some audio, video, and desktop sharing features require the installation of Silverlight. Note that because of the enhancements to Lync Web App, an updated version of Attendee isn't available for Lync Server 2013.

A Top Contender

For users, the changes to Lync's functionality (e.g., IM, conferencing, Enterprise Voice) and client will make Lync 2013 easier and more intuitive to use compared with previous editions. For IT administrators, the changes to Lync Server 2013 (e.g., consolidated roles, RBAC changes, enhanced Enterprise Voice infrastructure) and client will make designing, deploying, and managing the UC environment easier.

The fact that Microsoft hasn't changed some of the basics and is keeping the editions the same is great. You'll still have the option of choosing the Standard or Enterprise Edition, depending on which deployment model best suits your environment. I'm intentionally staying away from discussing sizing numbers until the product becomes a little more solidified, but suffice it to say that the Standard and Enterprise Editions can reportedly host a considerably higher number of users compared with Lync Server 2010.

Being a consultant who does Lync designs and implementations, I can personally say I'm delighted to see the consolidation of the Front End Server roles, the enhanced integration with Exchange 2013, and the evolution of Persistent Chat. The enhancements in Lync Server 2013 are clearly making it a top contender in the UC market.