Test Drive: Microsoft Lync 2010

What’s in a Name?
Microsoft Office Communications Server (OCS) is now Microsoft Lync 2010 and wow the changes are much more than just the name.

Not just a pretty face
Communicator in Lync 2010 has taken on a different look and feel from the OCS 2007 version. The multi-coloured balls are gone, replaced with photos and side bar presence indicators.  Photos can be stored in AD and can be linked with SharePoint as “Default Corporate Picture” or you can also show a picture from a web address as well. A new contact card pops up when you hover over a name giving details about that person.

One of the great features of this interface is the dial pad. Although there are many ways to place a phone call in Lync 2010, when you click on the telephone icon in the user interface, the more traditional dial pad appears.  The dial pad was available in OCS 2007 but you had to click around to find it.  The more in-your-face dial pad helps users transition more easily from a dial-by-number to a presence-enabled-dial-by-name paradigm.  It also sometimes makes Communicator easier to use when dialling mnemonic numbers (like 1800CARWASH) or when you have to enter conferences in which you must press * or #.  OCS 2007 and Lync 2010 both allow a user to type a mnemonic into the Communicator dialling interface and Communicator dials the proper digits – that’s cool!

The Lync 2010 interface takes advantage of this dial pad by integrating a voice mail pane in the window frame.  Exchange Unified Messaging voice messages display in the Communicator window and clicking on the message brings up the voice mail message from Exchange, which also shows text translation as well as an interface to play the message.

This new interface no longer has the video button or a meeting button on the main contact screen. These functions can be accessed through drop-down menus, from a contact card, or from an instant messaging window.

Social Networking
The Lync 2010 Communicator has two features that support social networking. The first is “Activity Feeds”, which gives users the ability to type a short message about what they are doing or thinking. This message is displayed on anyone’s Communicator interface that follows that person’s presence status.

What is a much more interesting capability is a skills search. In addition to being able to search by name, Lync 2010 allows users to enter keywords or text and then search to find someone who has that keyword or text associated with their name and contact information.  For example, in a hospital searching for Radiologist would bring up all staff who match that profile and show their presence.  The information one can search on must be stored in a profile located within SharePoint.

Each person can create a skills profile manually, or the SharePoint can help create it since SharePoint’s indexing engine can pull data from content that users put into shared workspaces, blogs, or Wikis.

There is a strong tie-in with SharePoint for both photos and social networking and Microsoft is developing its products so that there are more synergies between them so that businesses will seek to deploy the entire Microsoft messaging and collaboration stack.

Server roles
One of the gripes in OCS 2007 was that many of the server roles had to have their own physical server box to run on. This caused what should have been a relatively straightforward deployment to become complex/expensive due to server proliferation.

In Lync 2010, consolidation of server roles has occurred so that many roles are co-located on the same Lync front-end server. An important change is that the Mediation Server role has been re-architected so that it can be co-located with other server roles on a front-end server.

In Lync there are two topologies: Standard Edition suitable for most deployments, and Enterprise Edition, with multiple front-end servers and backend SQL servers, for larger deployments requiring more redundancy and scalability.  Whether roles are collocated or require their own dedicated server depends upon the demands placed on the servers based on load.

The Mediation role can be collocated when connecting to a gateway, IP-PBX or a SIP Service Provider which supports Media Bypass functionality.  Scale isn’t really an issue anymore because if the device supports “Bypass” then media isn’t flowing through the Mediation service, and thus impact to the server CPU is negligible.

Server pools are more prominent with Lync 2010.  It turns out that companies need multiple pools for two reasons:

1.    Very large deployments

2.    Where you need to create multiple pools due to organizational boundary issues

With Lync 2010, using multiple pools is no longer the exception, but an approved and recognized topology. Besides the benefit of better performance, deploying multiple pools in Lync 2010 allows you to specify primary and secondary pools for each user. This allows users who may be registered with a particular pool to automatically failover to another pool should the primary pool registrar fail.

Also new in Lync 2010 is the ability to “drain” a particular front end server before taking the server down. Draining allows a server to gracefully be taken out of service by slowly removing all user connections and services to that particular server.

Pools can also be extended across a low latency WAN in a sort of a “Metro Pool” configuration. This is useful for resiliency and disaster recovery purposes. If front-end servers in one site go down, users are automatically serviced by servers located at the other site.

Lync 2010 will support virtualization of all server roles. This is a significant improvement from OCS 2007.  This new full virtualization capability enables organizations to further reduce the physical server count. Lync 2010 virtualization works with Microsoft’s Hyper-V R2 and VMware but a detailed design exercise needs to be undertaken to make sure that sufficient virtual resources are provided to each server role.

Branch Survivability
A key element of a robust telephony solution is remote site survivability.  Lync delivers Survivable Branch Appliance (SBA) and Survivable Branch Server (SBS) options for redundancy.  Essentially, an SBA is a subset of Lync 2010 (the registrar and mediation service) running on a processor within a gateway at the branch office and SBS is the same running on a local server on the site.

SBAs provide a local failover solution so that voice calls can continue to be made even if the WAN fails.  Calls between users in the branch still traverse the local LAN; calls to other company locations and external parties traverse the PSTN.

Call Admission Control
In Lync 2010, Microsoft has introduced call admission control. Administrators can set voice and video bandwidth limits on a particular subnet or WAN segment, and bandwidth controls can also be set for individual users.

Bypass and 1-to-Many
The Mediation Server has undergone two fundamental changes that make OCS deployments easier. The first is called Mediation Server bypass. In Lync 2010, communications between a Communicator user (or phone) can bypass the Mediation Server entirely if the Mediation Server does not need to be involved. This is a significant shift from OCS 2007.  Mediation Server bypass will be useful for those deployments in which there is a PBX or gateway and calls are egressing to the PSTN or the call is connected to an internal PBX which supports commonly used audio codecs.  In these instances, the wideband audio capabilities of Microsoft’s Real Time Audio codec are not available anyway since the other side of the call is on the PSTN or in the PBX, so it makes no sense to require the Mediation Server to transcode the audio stream. Communicator has other standard audio codecs natively built into its stack (i.e. G.711, G.722, etc.) to handle these situations. Call signalling will still traverse the Mediation Server, however.

The Mediation Server role can be collocated on a front-end server when an organization deploys a voice architecture that supports Media Bypass functionality. Scaling the co-located Mediation Server role in for this architecture is not an issue because only signalling, not media, traverse the Mediation Server. If an organization deploys an architecture which does not allow media bypass, then the Mediation Server role should be separated.

Mediation Server bypass is not used when a leg of the call must traverse a corporate WAN with limited bandwidth. In this instance, Microsoft’s RT Audio narrowband codec will be used between the Communicator endpoint and the Mediation Server, and the Mediation Server will transcode to G.711 going to and from the PSTN gateway. Determining which WAN segments use bypass and those that do not is configurable.

The Mediation Server is also required when a PSTN call is routed to a remote worker outside the NAT and Firewall. In this instance, the Mediation Server acts as an Interactive Connectivity Establishment (ICE) client to enable these media flows.  The second major change made to the Mediation Server is that it no longer requires a 1-to-1 relationship between Mediation Servers and gateways.  In Lync 2010, a single Mediation Server can support many gateways simultaneously. This cuts down significantly on server proliferation as well as the IT maintenance.

With Lync 2010, the separate Live Meeting client has disappeared, but the functionality remains in a tightly integrated set of capabilities that include desktop and application sharing, PowerPoint presentations, whiteboard, and polling.  Audio conferencing and web conferencing is added to the standard Communicator client.

Integrating web conferencing into Communicator allows the RoundTable video conferencing device (Polycom CX5000) to provides a panoramic view natively with Communicator whereas prior to Lync 2010, you could only get the panoramic view in a Live Meeting session.

For video, the availability of 720p video came in OCS 2007.  What’s new in Lync 2010 is the ability for IT managers to control video bandwidth.  Third parties who want to integrate their video solutions with Lync 2010 must implement Microsoft’s RT Video codec for high definition. If they do not, then all a third party will get is CIF sized H.263 video.

Planning and Management
To help IT administrators more easily deploy and manage a Lync 2010 deployment, several very useful tools have been created:

1.    Planning Tool: this tool allows an administrator to put in basic information about the number of users, number of simultaneous conferences, whether to support remote users, branch offices, etc. The planning tool then builds a list of the Lync 2010 components required, including a list of all the servers the organization will need.

2.    Topology Builder: this tool takes information from the Planning Tool and helps the administrator create a Lync 2010 topology, identifying where each piece of hardware should go, the bandwidth required between WAN segments, etc.

3.    PowerShell: PowerShell has proven a very popular command line interface for both Exchange and SharePoint. Lync 2010 now has its own PowerShell command line interface.

4.    Control Panel: a Silverlight web application that provides an interface to all of the configuration, routing, and policy rules in the deployment.

In Lync 2010, a new Central Management Store has been created that contains all topology data, policies, and configuration information. This data all resides in a central management server, and one management server is deployed per pool (this is not a separate server). Changes to the configuration are automatically replicated to each server.  In addition, the central management server contains all of the telephone number translation and routing rules, which are also automatically pushed out to all Mediation Servers.

One of the signs of a maturing product is the availability of tools that make deployment, monitoring, and maintenance of that product easier. Microsoft has gone to great lengths to provide these types of tools for Lync 2010, which should greatly facilitate successful deployments.


There are too many improvements and new capabilities in Lync 2010 to mention them all here. What is clear is that Microsoft has made major strides toward improving OCS with Lync 2010 and it is ready for large scale, prime time deployments.