The Avaya Aura® system in domain 1 is configured to use Inter-PS federation to allow its users to watch Avaya Aura® and Microsoft users in domain 2. Signaling for Avaya Aura® users watching Microsoft users in domain 2 is tandemed through the Presence Services in domain 2. All signaling is routed through Avaya Session Border Controller for Enterprise at the edges of each domain. Use of Avaya Session Border Controller for Enterprise is optional, since no message manipulation is required, but recommended to protect each domain from the public network.

Since both Avaya Aura® and Microsoft users are in the same external domain that is, domain 2, a single set of configuration rules routing to that domain are required. For more information, see Checklist for configuring federation between two Presence Services clusters on different System Managers.