/mcpTSP reports the Whisper call state in the extended call state bit as CLDSMT_CALL_WHISPER_STATE. If the call is being put on hold because the destination is answering an intercom call by using talk back, the system reports the call reason CtiReasonTalkBack in the extended call reason field for the held call. The application cannot set line features, such as set call forwarding and set message waiting, other than to initiate the intercom call, drop the intercom call, or talk back. After the intercom call is established, the system limits call features for the intercom call. For the originator, only LINECALLFEATURE_DROP is allowed. For the destination, the system supports only the LINECALLFEATURE_DROP and TalkBack features for the whisper intercom call. After the intercom call becomes two-audio after the destination initiates talk back, the system allows only LINECALLFEATURE_DROP at the destination. Speed dial labels support unicode. IPv6 The IPv6 support feature enables IPv6 capabilities in a Unified Communications Manager network. IPv6 increases the number of addresses available for network devices. TAPI can connect to Unified CM with IPv6 support if the IPv6 Support feature is enabled on Unified CM. IPv6 enhancements include the following: • Provides the IPv6 address of the calling party to the called party in the Devspecific part of LINECALLINFO. • Support to register a CTI port or a route point with an IPv6 address. The RTP destination address also contains IPv6 addresses if the same is involved in media establishment. The TSP user interface includes the primary and backup CTI Manager address and a flag that indicates the preference of user while connecting to the CTI Manager. CTI ports and route points can be registered with IPv4, IPv6, or both. The following new CiscoLineDevSpecific functions allow the application to specify IP address mode and IPv6 address before opening CTI port and route point: • CciscoLineDevSpecificSetIPv6AddressAndMode • CciscoLineDevSpecificSetRTPParamsForCallIPv6 For dynamic port registration, on receiving the SLDSMT_OPEN_LOGICAL_CHANNEL event, the CciscoLineDevSpecificSetRTPParamsForCallIPv6 allows the application to provide IPv6 information for the call. Interface Changes See Set IPv6 Address and Mode, on page 377. Message Sequences See IPv6 Use Cases, on page 863. Backward Compatibility This feature is backward compatible. The 0x00090000 extension must be negotiated to use this feature. Cisco Unified TAPI Developers Guide for Cisco Unified Communications Manager, Release 15 and SUs 73 Features Supported by TSP IPv6