The ideal configuration for Deployment Manager to be installed on a separate Pega environment, referred to as an orchestrator. The reasons to install the Deployment Manager application in a separate environment is
Ensure that the orchestrator environment is stable and it not impacted by development and testing activities that happen as part of standard development and release practices
A single orchestrator environment can be used to manage multiple application pipelines across many different Pega environments
It can connect to all the different target environments safely. There are often policies in place to prevent lower environments from being able to connect to higher environments and this way you can authorize just the orchestrator to connect to all the target environments and lock down access to the orchestrator. This is the model that matches other tools such as Jenkins, XLDeployand so on.
The orchestrator environment can be a standard Pega environment configuration typically used for a development environment
This orchestrator environment connects to all the other candidate environments that make up the application pipeline. The orchestrator communicates to the other environments through http or https on port 443.
The candidate environments also need to connect to the orchestrator environment to send updates and responses using http or https via port 443.
The orchestrator environment also connects to Jenkins if Jenkins tasks are used as part of the pipeline.
There are also artifact repositories (Development Repository and Production Repository) that are used to store the application artifacts (such as product rule export archives). All of the environments connect to the repositories as that is way that the Development environment will publish and share the archives to the higher environments.