In a survivable remote environment, each gateway is manually configured with a list of call controllers during initialization and each IP endpoint can be manually configured with a list of call controllers during initialization or the Call controller settings can be downloaded to the endpoints. If for any reason, the communication between a gateway and its primary controller stops, the gateways and the IP endpoints register with a call controller on its list. If the survivable remote server is in the list of call controllers, the gateway and the IP endpoint registers with the survivable remote server. The gateway registers with the survivable remote server first before the IP telephone registers with the survivable remote server.

The Media Gateway Controller list can have Processor Ethernet addresses of main or survivable servers or Avaya Session Border Controller for Enterprise addresses prefixed with Session Border Controller for Enterprise in an Edge Friendly configuration. The list can contain up to 4 IP addresses/FQDNs.

The Processor Ethernet (PE) interface on a survivable remote server is used for:

• Connectivity to three adjuncts: Call Detail Recording (CDR), Application Enablement Services (AES), and Call Management System (CMS).
• H.323 and H.248 registration.

For more information on Processor Ethernet, see Processor Ethernet overview.

You can have both survivable core servers and survivable remote servers in a survivable core server configuration.

In an Edge Topology, a survivable remote server can be deployed within a cloud-connected branch office or within a distinct sub network behind a Network Address Translation (NAT) device. In this mode, the survivable remote establishes a connection to the main Communication Manager through a single WebSocket tunnel, which also facilitates remote access. If the remote branch office becomes isolated, the Local Survivable Processor (LSP) assumes control of call functionalities, operating as a Local Survivable Server similar to the setup in the enterprise (non-Edge) topology. For further details, see Administering Avaya Aura® Communication Manager.