RSSDP is a .NET library implementing the Simple Service Discovery Protocol (SSDP) for UPnP device discovery and advertisement. The library enables applications to discover network services and advertise their own services on local networks using UDP multicast communication. It provides a clean separation of concerns with distinct components for device discovery (SsdpDeviceLocator), device publication (SsdpDevicePublisher), and network communication handling (SsdpCommunicationsServer). The library follows .NET best practices with interface-based dependency injection, proper IDisposable implementation, and event-driven architecture for device lifecycle events. It supports multiple .NET platforms including .NET Framework 4.8+, .NET 6/8+, .NET Standard 2.0, and Xamarin platforms via MAUI. The repository includes comprehensive unit tests, sample applications (console, MAUI, UWP), and generated documentation via DocFX.