One (pair of) Loadmaster(s) is deployed for load balancing all of the Internal Lync Servers and External Lync Edge Servers.

Note: This means that Internal and External traffic traverses the same LoadMaster unit. As a result, a denial of service could impact both the internal and external Lync Server deployment.
Note: This deployment option departs from the Microsoft recommended standard, as described in http://technet.microsoft.com/en-us/library/gg398478(v=ocs.14).aspx, and may cause some issues in certain network configurations.