DNS load balancing is introduced in Microsoft Lync Server 2010. The objective of DNS load balancing is to provide a native load balancing mechanism option in Lync Server 2010. DNS load balancing can be quickly and easily configured in Lync Server 2010 and is a very cost effective option for load balancing. Lync Server 2010 DNS load balancing supports “connection draining.”
Read more at source: http://blogs.technet.com/b/nexthop/archive/2011/05/25/dns-load-balancing-in-lync-server-2010.aspx
Cheers,
Anderson Patricio
http://blogs.msexchange.org/patricio
Twitter: @apatricio