I have the skillset and practical approach necessary to implement a prototype in Java which detects incoming SIP/VoIP calls. The desktop app must work standalone on Windows, macOS, and Linux, and must communicate with a SIP provider. My code will pass Checkstyle, PMD, and Spotbugs, and I will use JDK17, Maven, and 24/8 formula. I will create a model class representing the input of my function, a service class implementing the logic, and a unit test. I am comfortable using Selenium and Apache Commons, but will seek prior clearance for any other libraries. I understand that the runtime is JRE, and that delivery should be made in your Git repository. I am open to working on additional tasks to implement a full app, and if I do a good job, I am open to integration into regular work and receiving additional SIP implementation tasks. Please let me know your best bid so that I can make an offer.