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
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.”