Placement

A Director pool should generally be placed in a location where the majority of the user base exists since it will be the initial point of sign-in for all users. It makes sense to place a Director in a datacenter with a Front End pool, and it’s unnecessary to use a Director in branch office locations with small user counts. A backup Director pool with a slightly higher SRV record priority can be placed in a secondary datacenter. This ensures that internal clients can still locate a Director for sign-in even if the primary Director pool is unavailable due to a WAN or datacenter outage.

Another recommendation when planning for placement is to use a Director in any location where an Access Edge server role exists. This way, as unauthenticated traffic from the Internet is passed to the internal network, the Director is just a short hop away from the Edge server and can authenticate the traffic quickly. If the Director were in another physical location, that traffic from an Edge server would have to traverse a WAN connection before even being authenticated.

In remote locations where it might make sense to deploy an Edge server to support local media paths, it isn’t necessary to deploy a Director. This is because the signaling traffic a Director sees is used only between the Access Edge server role and the Front End pools, unlike the media paths that flow between the endpoints shown in Figure 9.4.

Figure 9.4. Signaling and media paths with a Director and Conferencing Edge server in an additional site.