Redundancy allows the DNS server to give multiple SIP Server names in the answers to SRV lookups. Each server is monitored using periodic messages; the highest priority answer that can be reached is used for signaling.

To configure SIP server redundancy:

  1. Choose VoIP > Survivability.

  2. Scroll to SIP Server Redundancy Configuration.

  3. Configure settings using the information in the following table as a guide.

    SIP Server Redundancy Parameters

    ItemDescription

    Authorization User name

    Specifies the username to be used in authorization response.

    PasswordSpecifies the authentication password.

    SIP Server Redundancy Configuration

    Allows the DNS server to give multiple SIP server names in the answers to SRV lookups. Each server is monitored using periodic messages. The highest priority server that is currently reachable is used for signaling. Refer to IMS Proxy Reachability Detection.

    Enable SIP server redundancy

    Select the checkbox to enable monitoring of multiple SIP servers. A lower priority SIP server can be used if connectivity to the main SIP server is lost.

    Enable forward next REGISTER

    		Select the checkbox to forward the first REGISTER message from each SIP client to the softswitch after it becomes available. After the first REGISTER has been sent, normal REGISTER rate-pacing begins.

    Enable sticky failover mode

    		Select the checkbox to allow the Survivability module to stick to the failover server and discourage switch back to the failed higher priority softswitch.

    Enable SRV Lookup

    Checkbox is selected by default. Allows service record (SRV) lookup for the SIP server FQDN. If SRV Lookup is disabled (checkbox is un-checked), the system uses A-Lookup only.

    Enable 503 response

    Select the checkbox to enable 503 response for SUBSCRIBE with transparent mode after server failover. With SIP server redundancy enabled, if there is a loss of connectivity to the SBC detected (Options or SIP message counter), existing active subscriptions do not terminate until expiration, which can cause a service outage for phones using SCA/BLF.

  4. Click Submit to save your settings.
  5. Proceed to Configure Local Call Control.