Sequential Registration fail-over support for analog and digital endpoints

Last Updated : Sep 23, 2020 |
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You can configure the Sequential Registration fail-over support for Device Adapter analog and digital endpoints, that are on an MGC, in an event of a network failure either by allowing new registration requests or blocking new registration requests.

Fail-over support for analog and digital endpoints by blocking new registration requests

You can configure fail-over support for analog and digital endpoints by setting Max. Simultaneous Devices to 1 and selecting the Block New Registration When Maximum Registrations Active check box, which blocks any new registration request.
This configuration prevents another device from using the Device Adapter station registration through Sequential Registration. Hence, the Device Adapter station need not recover the station identity.
Till Device Adapter Release 8.1.1, the preceding configuration caused a delay when the SIP connectivity between the MGC and Device Adapter or between Device Adapter and Session Manager was lost, and endpoint registration failed over. The registration was delayed till the time the keep-alive signaling detected a connectivity loss, and Session Manager un-registered the current SIP registration and allowed a new SIP registration.
In Device Adapter Release 8.1.2, Session Manager identifies an endpoint for registration by using the device ID. If the MGC detects a registration failure, then depending on the deployment model, the MGC tries to re-register the endpoint either on the same cluster or alternate cluster. Because the device ID is the same, Session Manager processes this request as a re-registration request rather than a new request and registers the endpoint. This results in faster fail over.
Avaya recommends that you use this method to provide fail-over support for analog and digital endpoints.

Fail-over support for analog and digital endpoints by allowing new registration requests

Use the Sequential Registration configuration, that is, allow new registration requests, to provide fail-over support for analog and digital endpoints.
Depending on where the outage occurred either the MGC fails over to an alternate Device Adapter instance within the same cluster or Device Adapter may register to an alternate cluster.
The following are the scenarios:
  • In an N+1 cluster, if a Device Adapter instance on a primary cluster (primary Avaya Breeze® platform) loses connectivity, the endpoints fail over to another Device Adapter instance within the same cluster.
  • In an N+1 cluster, if the one cluster loses connectivity, the MGC on that cluster fails over to the Alternate 1 cluster.
  • If the connectivity between the primary cluster and Session Manager is lost, every MGC on the primary cluster fails over to the Alternate 1 cluster.
However, the use of Sequential Registration to provide fail-over support for analog and digital endpoints is not recommended because of the following reasons:
  • If a digital or analog endpoint gets unregistered, the MGC of this digital or analog endpoint immediately tries to re-register the endpoint. There is no mechanism to prevent the MGC from immediately trying to re-register a digital or analog endpoint that gets unregistered.
    Because the configuration is to allow new registration request, if a 96x1 or other SIP device tries to sequentially register, Session Manager unregisters a currently registered digital or analog endpoint. The MGC of this digital or analog endpoint immediately sends a SIP re-registration request to Session Manager, and repeats the re-registration attempt until the registration succeeds. This process unregisters the 96x1 or other SIP device.
  • Sequential Registration verifies station compatibility to a limited extent to prevent a user from logging in at an incompatible station definition.
    When a user uses analog or digital endpoints, the user cannot log in with the same user identity at any other device, that is, Avaya Aura® SIP endpoint or UNIStim endpoint.