Add A/V MCU Pool
All Enterprise Edition Front End Servers of a central site that do not have a collocated A/V Conferencing service can use the same stand-alone A/V Conferencing pool. For each A/V Conferencing pool, you must specify a fully qualified domain name (FQDN) for the pool and whether it will have only a single A/V Conferencing Server or multiple, load-balanced A/V Conferencing Servers.
You cannot convert a single-server pool to a multiple-server pool. If you later decide that your organization needs a multiple-server pool, you must delete the single-server pool, and then add the multiple-server pool.
If you plan to implement an A/V Conferencing pool in the future, select Multiple computer pool. Even though a pool is defined as two or more computers that are load balanced, you can create a single computer pool and create a pool FQDN for the single computer. When you are ready to add more computers to the pool later, you must Topology Builder again to define the new pool member, publish the new topology, and then set up the new A/V Conferencing pool member through the Skype for Business Server Deployment Wizard. A/V Conferencing Server pools are unique in that they do not need load balancers to create a pool. A/V Conferencing pools load balance internally and do not need additional hardware.