Support for Split-Node Deployments
The Siemens OpenScape PBX can be configured to operate in a SIP Business Continuity configuration. There are two supported modes:
- High-availability pair configuration, in which two OpenScape Voice nodes are physically located in the same area and share the same IP address for initiating and receiving calls.
- Split-node configuration, in which each OpenScape Voice node is geographically separated from the other. In this configuration, each PBX node has its own IP address on different subnets. Each node can be active for certain DNs; so, when a failure occurs, the remaining node will handle all calls, without taking over the IP address of the failed node.
Previous deployments of SIP Server with OpenScape Voice utilized only the first mode. Beginning with release 8.1, SIP Server supports a split-node configuration.
In a split-node configuration of the OpenScape Voice (with the same SIP Server), each OpenScape Voice node has a different IP address on different subnets. When both nodes are active, calls from each node arrive at SIP Server (typically, each node handles a subset of DNs). SIP Server recognizes all calls as coming from the same switch, as both nodes are part of the same OpenScape Voice switch.
When one of the OpenScape Voice nodes fails, the remaining node takes over all existing and future calls. SIP Server will handle existing and future calls to and from the remaining node, which has a different IP address on a different subnet. This take-over process will be transparent to endpoints (which are registered at the OpenScape Voice switch and will be re-registered at the remaining node in case of failure), to agents, and to Genesys T-Library client applications. See the Split-Node Deployment figure.
Feature Configuration
To support the split-node configuration, all OpenScape Voice (or PBX) nodes are represented in the configuration environment as a single Voice over IP Service object with the service-type option set to softswitch.
All PBX nodes share the same FQDN, which could be resolved through the DNS SRV records. DNS SRV records must be administered in such a way that the IP address of the node, in which endpoints are registered by default, has the highest priority. SIP Server tests the availability of all resolved addresses by using OPTION requests. The available address with the highest priority is used for SIP communication. If the original node fails, endpoints are re-registered at an alternative node. SIP Server starts using the alternative node when it discovers that the original node is not available.
The Configuring Split-Node deployment table lists the tasks that are required to configure the SIP Server and DN objects to support SIP Business Continuity with the Siemens OpenScape PBX.
|
Objective |
Related procedures and actions |
|---|---|
| 1. Configure each SIP Server. | In the SIP Server Application object, in the TServer section, configure the following options:
|
| 2. Configure the Voice over IP Service DN. | Configure the DN of type Voice over IP Service with service-type set to softswitch with the following options:
See also the following table for additional configuration options for this softswitch DN. |
| 3. Configure Extension DNs. | Complete the following procedure: |
| 4. (Optional) Configure a Trunk DN. | For SIP Server to handle outbound calls, configure a DN of type Trunk with the following option:* contact=<FQDN of Siemens PBX>—This is the same value as configured on the softswitch DN. |
Feature Limitations
Verification of split-node functionality was done with geographically-separated nodes that were configured without RG8700 as a SIP Proxy Server.