There are many features to be excited about in the upcoming release of Communications Server ‘14’ but now that the NDA is lifted on discussing features I thought I’d start with one that’s near and dear to my heart – DNS load balancing. I had the “pleasure” of doing some very large deployments with OCS 2007 R1 and R2, by which I mean greater than 150K users, and DNS load balancing was always an issue. Specifically it caused architectural issues with the Director role, requiring companies to use GSLB for true redundancy. (If you’re not familiar with the Director, check out my previous post on the topic, where I discussed some of these issues.)
Keith Hanna beat me to the punch and has written as article going through the DNS Load Balancing details which can be found here. The short version is that multiple IPs are associated with a pool which Communicator caches and connects to at random. In the event of a failure it will select another IP.
On a related note, the Director will be a proper role in Communications Server ‘14’ as opposed to how it worked in OCS 2007/R2. One of the key advantages to this is that you will be able to use load balancing without requiring a SQL server installation to support the Director. Instead it will use a local SQL Express instance for its database needs.
