The PACS Server Framework is a framework for easily creating DICOM based servers.   The framework consists of a Windows Service (Leadtools.Dicom.Service.exe) that implements a user defined DICOM service.  The Windows Service provides the following features:

1. Handles DICOM connections
2. Handles DICOM association negotiation
3. Supports DICOM Message addins that allow user supplied addins to respond to dicom messages.

This framework allows  a developer to quickly develop scalable full featured PACSS (i.e. Windows Service, Association and secure communications, debug and audit log).  It allows the developer to organize DICOM services into different processes (i.e. LAN vs WAN, secure vs unsecure, HIS/RIS vs PACS Archive).

The PACS Server Framework exposes specific interfaces that allow addins to implement additional functionality for the server.  The following features can be provided by addins:

1. Specify supported presentation contexts
2. Respond to specific dicom messages
3. Can spy on dicom communication without affecting the message
4. One addin can handle multiple DICOM messages.

Reference