Develop a simple Kamailio/OpenSIPS+RTPEngine/RTPProxy configuration

I am currently seeking a developer to create a topology hiding proxy with media relay for a SIP client project.

Project Specifications:

1. Develop a simple topology hiding proxy with media relay functionality.
2. No NAT traversal is required, as all clients will have public IP addresses.
3. The solution can be developed using Kamailio or OpenSIPS, and RTPEngine or RTPProxy.
4. The deliverable must include a Docker image and a corresponding Dockerfile.