impl. a prototype SIP/VoIP to detect incoming ringings

Your task is to implement a prototype (in Java), which detects incoming SIP/VoIP calls. On incomming call the desktop app opens a browser with a (caller-)URL. So the app has to work standalone on a desktop (windows, macOS, linux) and have to communicate with a SIP provider only. The caller-URL contains some query parameters, like the callers number. As a UI-less (cmd line only) app on the desktop it will be so a simply app which does basically a call listening and triggering a browser based URL to show. The environment: - one SIP account which has a real phone number - your SIP application to implement - one or more SIP desk phones - one ore more softphones (laptop, smartphone, ...) 1. your SIP application shall now detect incoming calls (rings) 2. if possible to detect which device has taken off hook (the call) 3. if possible how long the call was going with the different phone We have some exiting code of a proof of concept, which does not work anymore. So you do not start from scratch. But it is mandatory that you are a master of SIP+java to get to an success The listener shall be configurable, means - what URL to call - which phone numbers to ignore - which phone numbers to track (regEx) Please recommend what to use SIP-RI/SIP-Jain to detected phone calls. You will get a SIP/VoIP account to be able to implement and test incoming calls (if you do not have your own) Your task is to implement Java classes to be able to access details of incoming calls as a listener. Implement JUnit test cases, which is showing how the implemented listener is required to be configured (regex, ignore numbers, URL) The Q-question is a formula, place result into the bid. A good starting point for SIP starters may be: [login to view URL] [login to view URL] You need to implement for: - linux & windows (a basic java best practice and requirement, ensure system independent development) requirements: only call from JUnit (no UI) What is NOT needed: - a UI (not required, implement a JUnit test to call your functions) - a service architecture (like spring or JEE) - any persistence - a voice/audio implementation for SIP (only incoming ringing required) Milestones: MS1: very basic implementation of SIP [login to view URL] MS2: the rest of the above named requirements MS3: with and without TLS / SRTP support TLS / SRTP, shall be mandatory for later usage of this app What are our requirements? - your code passes checkstyle, pmd and spotbugs (we will share you a git repo with eclipse settings) - JDK17 - maven - 24/8 formula - create a model class representing the input of your function - create a service class implementing the logic - create a unit test, which tests the service class - we do NOT need a UI, we only need the model + service method to access the logic via JUnit - if you need libs selenium or apache commons are fine. Other libs NEED prior clearance - the runtime is JRE (no JavaEE nor Spring-container) - delivery in our git Outlook - we want to have a prototype/POC to fiddle around with the possibilities on our environment - after the prototype phase, we will have more tasks to implement to a full app, so preferably you/your team will get also this tasks - if you do a good job on supporting our team, we are open to integrate you into regular work and we will share you more tasks about SIP implementations What is our budget? we do not disclose our budget nor planned hourly rate. Offer us your best bid. Your bid? Place your best hourly bid. We do not want to negotiate with you anymore after getting in touch with you. So place your best bid to save time here Communication: Do not wait for our availability here. Just answer, just ask or just reply.