This document discusses some of the legal and technical challenges around open source software for voice over IP telephony. It notes that while some key codecs like iLBC and AMR have open implementations, their use may still be restricted by patents. It also cautions that not all open source projects are fully free and open, and some protocols remain proprietary. Overall it presents both opportunities and risks regarding openness, interoperability, and freedom around voice communication standards and implementations.

1. Logiciels libres en téléphonie sur IP: Pièges & menaces

2. Rappel: GPL v2 “To protect your rights, we need to make restrictions that forbid anyone to deny you these rights or to ask you to surrender the rights. These restrictions translate to certain responsibilities for you if you distribute copies of the software, or if you modify it.” - Preamble, GPL v2.1

3. Menaces

4. Brevets EP-1114414 EP-1224659 EP-1058927 EP-1008141 EP-877355 EP-503684 EP-0516621 EP-819303 EP-813736 AMR:

5. Brevets EP-1114414: Adaptive Combining of Multi-Mode Coding for Voiced Speech and Noise-Like Signals AMR: Brevet logiciel

6. Standards bodies ITU ISO/IEC

7. “ The Contributor grant a perpetual, irrevocable, non-exclusive, royalty-free, world-wide right and license to the ISOC and the IETF under all intellectual property rights in the Contribution: (e) to extract, copy, publish, display, distribute, modify and incorporate into other works ... any executable code or code fragments that are included in any IETF Document ... subject to the requirements of Section 5 (it also being understood that the licenses granted under this paragraph (E) shall not be deemed to grant any right under any patent, patent application or other similar intellectual property right disclosed by the Contributor under RFC3979). http://rfc.net/bcp78.html

8. “ RAND” “ the originator shall ask any holder of such identified patent rights for a statement that the holder would be willing to negotiate worldwide licences under his rights with applicants throughout the world on reasonable and non-discriminatory terms and conditions” ISO/IEC IPR policy

9. Interoperability requires iLBC “ iLBC codec is standardized by IETF (RFC3951 and RFC3952) and is designated by CableLabs as a mandatory component of all voice-over-cable telephony systems.”

10. Interoperability requires iLBC Personal, non-commercial use is generally permitted. Commercialization is permitted with certain limitations; for example, to ensure that every iLBC decoder can decode every iLBC-encoded payload, commercial “Deployment” must comply with the applicable IETF Standard/draft, and the format of the bitstream may not be modified. You are provided no warranty or support, and all liability is disclaimed. You must register this license with GIPS prior to any commercial Deployment.

11. Danger

12. All that glitters is not gold

13. Source code != Libre

14. Les sources iLBC font partie du standard Une implémentation AMR disponible en bibliothèque: http://www.penguin.cz/~utx/amr

15. Protocoles propriétaires

16. Espoir

17. Protocoles, codes ouverts

18. mais...

19. Utilisation des codecs ouvert entre logiciels libres Implémentation de codecs compatibles GPL Interoperabilité à tout prix

20. FIN