Opensource billing solution -- 2

A Business and Residential VoIP provider company with a paid billing solution ([login to view URL]) needs a new opensource billing to replace the current one. The goal is to have a ‘pocket’ billing, which can be installed by a non-technician and which can replace the general criteria's and services which currently the company uses in Portabilling.  The license must be Open-Source  Documentation must be up-to-date and publicly available  A standard API(REST, SOAP, webservice…) allowing to interact with the system  There is a backup and restore system  A-Z documentation on how to install new billing system, which will be followed by a non-technician  Current multiple server network must be replaced by a simple architecture with few servers only So whoever will take care of this project must test all possible opensource billing solutions, make multiple tests to make sure it can replace the most important and vital processes which the VoIP company currently has. The internal documentations with already done tests, network diagrams will be shared with the developer(s) only after signing a confidentiality note, for which a copy of passport/ID is required. So whoever is not ready for this point, must not consider applying for this project.