We have reached part 3 of the Edge topologies; we begin with the "scaled single-site" topology. This is where we still have the server roles in the permiter network, however now we introuduce the concept of having them load balanced.
The scaled single-site topology can consist of all three edge server roles as the other topologies. Now this topology is very similar to single-site topology in the sense that the access edge (AE) and the web conference (WC) servers are collocated together and the audio\ video conference (AV) server is separated.
As stated before the scaled single-site topology is a little different because we introduce the concept of load balancers into the equation. So we can have two collocated AE and WC servers and a two AV servers. This example I just explained has 4 servers in the setup, recall 2 - WC & AE servers and 2 - AV servers all load balanced.
Regarding the load balaner (LB) you can leverage the same LB for all 4 servers; however we would leverage separate virtual IPs (VIPs) for each of the roles.
This topology is well suited for organizaitons that which to have redundacy in the perimeter network.