Associate Front End With Edge
Each Front End pool can have only one Edge Server or Edge pool associated with it. When you enable external user access for a site, you can provide support for remote users. You can also enable support for federated users, which can include support for users of specific public instant messaging (IM) connectivity providers (such as Windows Live), and support for anonymous users.
All pools at a site, and the pools of multiple central sites, can use the same Edge Server, if usage does not exceed the capacity of the Edge Server. For details about monitoring, including scaling, see Planning for External User Access in the Planning documentation. For details about designing a topology to support external user access, see Define Your Edge Topology in the Deployment documentation.