> For the complete documentation index, see [llms.txt](https://support.portsip.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://support.portsip.com/v16.x-maintenance-mode/pbx-cluster/configuring-cluster-servers-for-portsip-pbx-ha.md).

# Configuring Cluster Servers for High Availability

Once a PBX is deployed as the High Availability for On-Premise, it can also add additional servers for the cluster. Please reference the below architecture.

<figure><img src="/files/JCF8a4Wn9GG3dkuI2ilL" alt=""><figcaption></figcaption></figure>

## Configuring Cluster Servers for High Availability

To set up the cluster servers for a PortSIP PBX HA, follow the same steps as you would when configuring the cluster servers for a standalone PortSIP PBX. The only difference is that you should use the **Virtual IP** of the PBX HA instead of the PBX’s IP in the subsequent steps of the guide.

* [Preparing Cluster Servers](/v16.x-maintenance-mode/pbx-cluster/preparing-cluster-servers.md)
* [Configuring Cluster Servers](/v16.x-maintenance-mode/pbx-cluster/configuring-cluster-servers.md)