Topic Last Modified: 2011-03-15
The reference topology with limited high availability is for an organization that wants to deploy Microsoft Lync Server 2010 communications software functionality at a minimum cost. Typically, the specific topology shown in the following diagram is recommended for organizations with 5,000 or fewer users, although you can support additional users by adding additional Standard Edition servers.
- Active Directory deployment. All Lync
Server deployments reside in a single Active Directory forest. For
this topology, the customer has Lync Server deployed in the child
- Voice pilot. The organization using the
exact topology shown in this diagram is currently running a pilot
program of the Enterprise Voice feature of Lync Server. Some users
are using Lync Server as their sole voice solution.
If they go on to fully deploy Enterprise Voice and remove the PBX system, they should provide high availability for their voice solution by deploying a second Standard Edition server or moving to a Front End pool. A single Standard Edition topology as shown in this diagram is recommended only if you are not deploying Enterprise Voice in a production environment. Because being able to make calls is mission critical for almost every organization, you should provide high availability if you use Enterprise Voice as your telephone solution.
- Another Standard Edition server can be
added. A single Standard Edition server can
support up to 5,000 users. If you want to accommodate more users or
provide some high availability capability for Enterprise Voice (at
a minimum cost), you could add another Standard Edition server to
For a true high availability solution, you should deploy Enterprise Edition and deploy a Front End pool. Although having two Standard Edition servers would maintain Enterprise Voice functionality should one of these servers go down, a Front End pool provides much better continuity of service for other Lync Server features.
- Branch site survivability. This
organization is running the Enterprise Voice pilot with some branch
site users as well. The branch office does not have a reliable wide
area network (WAN) link to the central site, so a Survivable Branch
Appliance is deployed there. With this deployed, if the WAN link
goes down users at the branch site can still make and receive calls
(both calls within the organization and PSTN calls), have voice
mail functionality, communicate with two-party instant messaging
(IM). Users can also be authenticated when the WAN link is
unavailable as well.
- Edge Server deployment is
recommended. Although deploying an Edge Server
is not required for internal IM, presence and conferencing, we
recommend it even for small deployments. You can maximize your Lync
Server investment by deploying an Edge Server to provide service to
users currently outside your organization’s firewalls. The benefits
include the following:
- Your organization’s own users can use Lync Server
functionality, if they are working from home or are out on the
- Your users can invite outside users to participate in
- If you have a partner, vendor or customer organization that
also uses Lync Server, you can form a federated relationship
with that organization. Your Lync Server deployment would then
recognize users from that federated organization, leading to better
- Your users can exchange instant messages with users of public
IM services, including any or all of the following: Windows Live,
AOL, and Yahoo! A separate license might be required for public IM
connectivity with Windows Live, AOL, and Yahoo!
- If you also deploy the Lync Server XMPP Gateway, you can enable
your users to exchange instant messages with the users of providers
and servers that use Extensible Messaging and Presence Protocol
(XMPP), such as Google Talk and Jabber.
Note: To use XMPP, you must install the XMPP Gateway. You can download the XMPP Gateway from the Microsoft Download Center at http://go.microsoft.com/fwlink/?LinkId=204552. After you install the XMPP Gateway, you need to install the hotfix, which is available for download from http://go.microsoft.com/fwlink/?LinkId=204561.
- Your organization’s own users can use Lync Server functionality, if they are working from home or are out on the road.