1. Lync Server Standard Edition
The Standard Edition of Lync Server provides
a relatively simple way for small- to medium-sized organizations to
introduce unified communications into a network. It offers a relatively
low cost of entry based on the fact that all internal components are
hosted on a single server, with the option of adding an edge server to
support external connectivity.
Standard Edition utilizes a local SQL Server
Express Edition database to store Lync information, and the database is
installed automatically by the deployment wizard. Although Standard
Edition does not provide all the high-availability options that are
available with the Enterprise Edition, with Lync Server 2013 new
functionality has been added in the form of Front End Pool Pairing.
This new feature allows Standard Edition pools to be designed for a
level of resiliency, even across multiple sites. For this reason, many
organizations, will find that installing multiple Standard Edition
servers across several sites will result in an ideal combination of low
cost, site resiliency, and a solid set of features. The primary
disadvantage to Standard Edition is that it is designed to handle
relatively low user loads, because the all-in-one nature of the system
limits scalability in terms of performance. At the same time, the
consolidated design of a Standard Edition server makes it simpler
to deploy and maintain than an Enterprise Edition topology, and the
performance characteristics will be more than adequate for many
small-to-medium sized organizations.
A typical Standard Edition deployment would
involve a single system acting as a Front End server, which might
include additional collocated roles depending on the requirements, such
as Mediation Server, Archiving Server, Monitoring Server, and
Persistent Chat Server. To round out the deployment, a PSTN gateway can
be used to enable Enterprise Voice, and an Edge Server can be installed
to provide external connectivity. An additional system hosting the
Director role can optionally be used to redirect incoming user requests
to the Front End. This configuration is sufficient to provide IM,
voice, and video services for a small- to medium-sized organization, as
well as public IM connectivity, A/V conferencing, and more.
Note
Although Lync Server Standard Edition is
typically used in small-to-medium sized deployments, it is also quite
common for both editions to be used within the same architecture. For
example, some larger organizations deploy Enterprise Edition Lync pools
in primary data centers, and use Standard Edition pools to service
smaller, regional offices. The Enterprise and Standard editions of Lync
Server can easily be mixed and matched as needed within a network to
accommodate different levels of service and budget for different
locations.
2. Lync Server Enterprise Edition
The Enterprise Edition of Lync Server
provides a scalability jump compared to Standard Edition, and provides
additional high-availability options. The increase in scalability
results from the separating of roles onto separate systems for better
performance, and also the use of more robust components in certain
areas. For example, whereas Standard Edition can use only a local SQL
Express database, Enterprise Edition requires the use of a full SQL
instance installed on a dedicated system. In this one area alone,
scalability is improved not only by using a more robust database, but
also by isolating the database load from other systems.
In terms of high availability, Enterprise
Edition provides several advantages compared to Standard Edition.
Although the Front End Pool Pairing feature is available with either
edition, only Enterprise Edition allows for the failure of a Front End
server with no resulting loss of functionality for the pool users. This
is possible because Enterprise Edition allows the installation of
separate Front End servers for the same pool within a particular site.
An additional resiliency advantage is that Enterprise Edition requires
a separate database for backend data storage, which presents the
opportunity to leverage native SQL high availability for the Lync data.
Lync Server 2013 supports SQL mirroring, which requires two backend SQL
servers and uses data synchronization between the two systems.
Of course, the additional scalability and
high availability provided by Enterprise Edition come at a higher cost,
in terms of both additional systems and licensing. A typical Enterprise
Edition deployment at a given site consists of at least two Front End
servers (up to a maximum of 10 per pool), with hardware load balancers
(or a combination of hardware load balancers and
DNS load balancing) used to distribute the load between the systems. At
least one SQL server system would be used to store the backend data,
although two such systems with SQL mirroring would be recommended for
redundancy. On the Front End systems, several other Lync server roles
can be collocated, including Mediation Server, Monitoring Server, and
Archiving Server. The Mediation Server role can also be installed
separately from the Front End to increase performance. Other systems
that can be added to provide increased functionality with an Enterprise
Edition deployment include one or more PSTN gateways to enable
Enterprise Voice features, Persistent Chat Server, and an Edge Server
or Edge Server pool to support external connectivity.
Note
With previous versions of the product, the
Monitoring Server and Archiving Server roles were always installed
separately from the Front End Server, and the A/V Conferencing Server
role could be installed separately if desired. In Lync Server 2013,
each of these roles is collocated with the Front End Server with all
deployments. The Persistent Chat Server can also be collocated with the
Front End Server in a Standard Edition deployment, but must be
installed separately from the Front End with an Enterprise Edition
deployment. The Mediation Server role can either be collocated with the
Front End Server or installed separately depending on the specific
Enterprise Voice requirements of the deployment.
3. Client and Server Licensing
Microsoft licensing for Lync includes both
client and server licensing. Whereas the server licensing is
straightforward, the client licensing can be challenging to absorb. As
noted in the previous sections, there are two editions of the server
software: Standard Edition and Enterprise Edition. All Front End
Servers installed in a Lync deployment fall into one category or the
other, and must therefore be licensed appropriately.
Note
Whereas each Lync Front End Server must be
licensed for either Standard Edition or Enterprise Edition, any other
Lync servers in the environment are always licensed using Standard
Edition. This includes any systems hosting the Edge Server role, as
well as standalone systems hosting the Persistent Chat Server or
Mediation Server roles.
As for client licensing, one Client Access
License (CAL) is required for each user to access the services of a
Lync server. However, there are three types of CALs available for Lync
Server 2013:
• Lync Server 2013 Standard CAL
• Lync Server 2013 Enterprise CAL
• Lync Server 2013 Plus CAL
The Standard CAL is the
base CAL, which is required for all users and grants access to a
standard set of Lync features, including IM and Presence and
peer-to-peer audio and video communications. The Enterprise and Plus
CALs are additive CALs that grant access to additional Lync features.
Whereas the Enterprise CAL grants access to audio, video, and web
conferencing features, the Plus CAL includes Enterprise Voice features.
To enable access to the entire feature set provided with Lync, a user
must be licensed with all three CALs. Note that this is the case
regardless of the server edition installed on the Lync servers that the
user connects to.
The CAL types mentioned can all be
purchased individually as part of a standalone Lync deployment, and the
Lync Standard and Enterprise CALs in particular can also be purchased
as part of a volume licensing arrangement. For example, the Lync
Standard CAL can be purchased as part of the Microsoft Core CAL Suite
(CCAL), and the Lync Standard or Enterprise CAL can be purchased as
part of the Microsoft Enterprise CAL Suite (ECAL). Many organizations
purchase Lync licensing as part of a larger volume licensing agreement
in order to save on overall licensing costs. Note that the Plus CAL
must be purchased standalone, because it is not included in either the
CCAL or the ECAL volume license offerings. There is also a licensing
requirement for the Lync client software. The client software can be
purchased as a standalone application, or it is included as part of the
Office Professional Plus 2013 suite.
