mod_skinny currently is not believed to support IPv6 (as of 2014-06-17)

  There is a notation in the wiki that you can force IPv6 usage
  by setting: ip="::" in the profile, but unclear if that is sufficient
  for the rest of the protocol. 

According to Cisco documentation, the underlying protocol does support IPv6 for the "G" series
phones. (Basically a subset of the models running the java based image.)

http://www.cisco.com/c/en/us/support/docs/voice-unified-communications/unified-communications-manager-version-70/112997-cucmipv6-00.html 

	7906G, 7911G, 7931G, 7942G, 7945G, 7962G, 7965G, and the 7975G

It is possible that others would be supported, and are just not listed in the Cisco documentation
due to them being past end-of-life. 

Additional changes will be required to mod_skinny to actually support IPv6, at a bare minimum, the
current code has at least one data structure for the server response that contains a fixed
layout structure with uint32_t's for IP addresses.

If someone has an existing CCM deployment that is using IPv6, sample network captures would be
appreciated.