Survivable remote server

Last Updated : Nov 24, 2023 |

The survivable remote server provides survivability to IP and SIP telephones and one or more branch gateways when communication to the core is lost. The survivable remote server provides survivability for both Communication Manager and Session Manager.

A typical survivable remote solution contains the following components:

  • Survivable Session Manager that provides service to users in case there is a WAN failure between branch and core.

  • Survivable remote server (Communication Manager) for the branch gateway. The survivable remote server starts to work when the branch gateway loses connectivity with main Communication Manager and register itself to survivable remote server.

  • Branch gateway that provides the ability to connect the branch to the PSTN and media services as conferencing, tones, and announcements.

  • End user devices (telephones and video devices) that register themselves to core Session Manager as a primary controller, but uses the survivable Session Manager as a third controller in case of WAN failure.

The survivable remote server template can be installed on a simplex standalone server or on an embedded server.

Communication Manager

For Communication Manager the survivable remote server takes control of branch gateways that has its address in the Media Gateway Controller (MGC) list. The IP telephones use an Alternate Gateway List (AGL) for branch gateway addresses. These addresses are automatically generated by Communication Manager and sent to the IP telephones upon registration. Because the survivable remote server does not manage the procr, it cannot control port networks.

In a survivable remote environment, each IP endpoint and branch gateway is manually configured with a list of call controllers during initialization. If for any reason, the communication between a branch gateway and its primary controller stops, the branch 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 branch gateway and the IP endpoint registers with the survivable remote server. The branch gateway registers with the survivable remote server first before the IP telephone registers with the survivable remote server.

For more information on the survivable remote servers as it relates to Communication Manager, see Avaya Aura® Communication Manager Survivable Options.

Session Manager

Session Manager for Survivable Remote is a set of software packages that acts as SIP routing and user relation elements when in survivable mode. It is built with the same specifications as the core Session Manager, providing survivability services for trunks, SIP stations and applications.

In the branch office are the branch SIP endpoints and a branch gateway. The endpoints are registered to both the core Session Managers and the survivable Session Manager. The endpoints have the concept of an active controller. The active controller is defined as the Session Manager to which the endpoints currently have subscriptions established. In sunny day operations, the core Session Manager is always the active controller. The survivable Session Manager receives no call traffic. The branch gateway is registered with the main Communication Manager. In rainy day operations, the survivable Session Manager is always the active controller. Currently, the only supported network outage is a complete branch WAN outage where all devices in the branch have lost contact with all devices in the core. Partial network outages are not guaranteed to exhibit desired redundancy behaviors.

For more information on the survivable remote server as it relates to Session Manager, see Administering Avaya Aura® Session Manager.