> For the complete documentation index, see [llms.txt](https://knowledgebase.qommentary.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://knowledgebase.qommentary.com/getting-started/prerequisites.md).

# Prerequisites

Before installing Qommentary on-premises we recommend completing the following prerequisites checklist to ensure your host environment is ready for installation:

* [ ] Review minimum System requirements
* [ ] Open ports 5004 and 5006 inbound in Qommentary Server
* [ ] Open port 4242 (QRS) inbound in Qlik Sense Server
* [ ] Open port 4243 (QPS) inbound in Qlik Sense Server
* [ ] Install and configure IIS (*see* [*Software dependencies*](/getting-started/prerequisites/software-dependencies.md))
* [ ] Install QlikClient certificate (*see* [*Client Certificates*](/getting-started/prerequisites/client-certificates.md))
* [ ] Install SSL certificate to be applied to Qommentary server-hosted applications

#### System Requirements

| Requirement                                                                                       | Version                          |
| ------------------------------------------------------------------------------------------------- | -------------------------------- |
| <img src="/files/-M4UCM40Ny30PXxyP7xv" alt="" data-size="original"> Windows                       | Microsoft Windows 2008 or higher |
| <img src="/files/-M4UCVkWFUx-yKQxbbRz" alt="" data-size="original"> Internet Information Services | 8.0 or higher                    |

{% hint style="warning" %}
IIS need to be enabled on the server where Qommentary will be hosted. For a full list of required IIS features, please refer to our guide.
{% endhint %}

#### Database

Qommentary support the following databases:

| Database                                                                                 | Version       |
| ---------------------------------------------------------------------------------------- | ------------- |
| <img src="/files/-M4UNLo3MnqT1oExjOfi" alt="" data-size="original"> PostgreSQL (default) | 9.0 or higher |

{% hint style="info" %}
If desired, a new PostgreSQL instance can be fresh installed or connect to an excising instance during the installation wizard.
{% endhint %}

#### Ports

A Qommentary deployment requires 2 components to be hosted on-premises: the Qommentary Engine and the Qommentary Manager.&#x20;

These components communicate internally behind the firewall via dedicated ports and **no connection to the internet** is required.

The following ports need to be opened **inbound** on the server where Qommentary would be hosted:

| Qommentary Engine  | 5004 |
| ------------------ | ---- |
| Qommentary Manager | 5006 |

{% hint style="info" %}
If desired, ports can be changed during installation.
{% endhint %}

The following ports need to be opened **inbound** on the server where Qlik Sense is hosted:

| Qlik Repository Service (QRS) | 4242 |
| ----------------------------- | ---- |
| Qlik Proxy Service (QPS)      | 4243 |