Hi, I have been recently configuring kamailio IMS (v 4.3.4) for IPv6 user registration. I have my PCSCF Gm interface, ICSCF Mw interface and SCSF Mw interface all listening on IPv6 address on port 5060. PCSCF Rx interface is configured with IPv4 address to communicate with PCRF. Similarly ICSCF and SCSCF are also configured with IPv4 address to communicate with HSS (not Fraunhofer HSS) . My Linphone client configured with IPv6 address is sending register message to PCSCF. PCSCF throws the following error on while sending the AAR to PCRF *ubuntu kamailio[22627]: INFO: <script>: REGISTER (sip:001010000000004@TestNetwork (5555:0:0:1:ABCD:0:0:1:9060) to sip:001010000000004@TestNetwork, KFEtBsO-dm)ubuntu kamailio[22627]: ERROR: ims_qos [rx_aar.c:878]: rx_send_aar_register(): Unable to add framed IP AVPubuntu kamailio[22627]: ERROR: ims_qos [rx_aar.c:904]: rx_send_aar_register(): unexpected errorubuntu kamailio[22627]: ERROR: ims_qos [mod.c:1145]: w_rx_aar_register(): Failed to send AARubuntu kamailio[22627]: ERROR: ims_qos [mod.c:1189]: w_rx_aar_register(): Error trying to send AARubuntu kamailio[22627]: WARNING: tm [t_lookup.c:1476]: t_unref(): WARNING: script writer didn't release transaction* On debugging, I found that the ip version is hard coded to AF_INET.( a comment is also written TODO: IPV6 support) in ims_qos/mod.c file. On changing it to AF_INET6 ( I did this 'cos I saw IPv6 based checking on other files like "ims_qos/rx_avp.c") I can see AAR from PCSCF to PCRF, but Framed IPv6 Prefix AVP is incorrect. So, I would like to know if ims_qos module supports IPv6 address ? Regards, Ayon