But here's the catch: With the Enterprise Edition, only some of Lync's features, called "server roles," can be colocated on the same physical servers (reference architecture is here). According to Microsoft, many specific server roles "must each be deployed on a separate computer." This includes Director, Edge Server, Trusted Application Server, Group Chat and others. Using Microsoft's reference architecture of 14 servers, Lync can support "upwards of 80,000 users," Microsoft says.
But there's another catch, too. For such large-scale deployments, Lync Enterprise Edition "requires the use of load balancers," a Microsoft spokeserpon says. "Enterprise Edition Servers are deployed in 'pools' which support up to 10,000 users per server and 80,000 users per pool." (Reference here.)
Plus, Microsoft recommends that Exchange be run on its own servers, too.
For the small business, Microsoft says the Standard Edition supports up to 5,000 users. It also says that the Standard Edition supports failover, contrary to popular belief that it doesn't. "This is new with Lync: users fail-over from one Standard Edition Server to a second and failover does not require load balancers."
Morimoto points out that these support numbers don't tell the whole story for telephony services, either. The configuration is really dependent on how many users can be expected to be on the phone concurrently. Morimoto will confidently put 5,000 users on a single Lync Instant Messaging server and 2,000 people on a single Web conferencing server.
For telephony, he says he typically figures on one server for every 100 concurrent users. On average, Morimoto estimates that for many companies, about 10 percent of the employees are on the phone at any given time, meaning one server can likely handle 1,000 users. Ergo, a company with 5,000 people, would likely need five servers. On the other hand, with virtualization, this doesn't necessarily mean purchasing a lot of new hardware. "A company with that many people is going to be in three or four buildings. So you will probably have a server in every building anyway," he describes.
The upshot is that running a multitude of Lync's features means needing access to a good number of physical servers, plus load balancers. Lync will also need Microsoft-approved optimized SIP phones or Windows desktops to function as full-featured phones (with Mac support coming soon).
Another legitimate complaint Schurman lobbed at Lync was that it was far more expensive than users expected. Like every other Microsoft product, a discussion about Lync licensing feels like falling down a rabbit hole. Lync has a reputation of being free because when Lync was introduced, users who had already had the Microsoft Office Communications Server Enterprise client access license and a Software Assurance agreement, got the Lync Plus CAL for free.
That deal no longer exists, although most Microsoft customers will not have to pay extra for the Lync Enterprise Edition CAL. It is included in the Enterprise CAL Suite, which covers Windows Server, Exchange, SharePoint, System Center, and Forefront as well as Lync.
However, when using the Lync Enterprise Edition, other licensing may apply, such as a requirement to license SQL Server. Microsoft confirms that the Enterprise Edition uses SQL Server for the backend server and therefore Microsoft requires Lync users to have a valid SQL Server to cover that server.
Again, small businesses could be spared as "Lync Server Standard Edition users need no separate SQL license," a Microsoft spokesperson says.
In all fairness, these drawbacks in Enterprise Lync have caused many more untrue rumors to circulate about the product, too.
Microsoft has dismissed some of them: Lync does support site-to-site failover. In a well-planned system, if one server role goes down, the others need not be affected. And Direct SIP, Microsoft's interconnection with PBX systems, supports multiple vendors' products, Microsoft says. These include Cisco and Avaya.
Julie Bort is the editor of Network World's Microsoft Subnet and Open Source Subnet communities. She writes the Microsoft Update and Source Seeker blogs. Follow Bort on Twitter @Julie188.
Read more about lans and routers in Network World's LANs & Routers section.