iLBC license issue

[Jan Janak]

Hello,

kphone (and maybe other packages) contain iLBC (internet Low Bitrate Codec)
library. This library has been published as part of RFC3951 by the IETF.

The copyright owner of that code is Global IP Sound and the license of the
code is not GPL compatible. The license requires that derived work must
be backwards compatible with the original specification. This is more
restrictive than GPL.

I am wondering whether the people on the list are aware of this ? The
copyright file in kphone package says that it is released under the terms of
GPL, but I wonder if this is true when iLBC is included ? Shouldn't kphone
be moved in non-free ?

http://www.ilbcfreeware.org/documentation/gips_iLBClicense.pdf

  Jan.