Restrictions for Conferencing and Transcoding for Voice Gateway Routers

• DSP resources communicate with Cisco Unified CallManager using Skinny Client Control Protocol (SCCP). Other protocols are not supported.

• DSP resources cannot be enabled for a slot on the Cisco 1700 Series so the dsp services dspfarm command is not supported and cannot be configured for a voice card on the Cisco 1700 Series.

• Conferencing is not supported on a Cisco 3640 using the NM-HD-1V, NM-HD-2V, or NM-HD-2VE.

• Hardware MTPs support only G.711 a-law and G.711 u-law. If you configure a profile as a hardware MTP, and you want to change the codec to something other than G.711, you must first remove the hardware MTP by using the no maximum sessions hardware command.

• Software MTPs are supported on the router only if the dsp services dspfarm command is not enabled on the voice card.

• Only one codec is supported for each MTP profile. In order to support multiple codecs, you must define a separate MTP profile for each codec.

• If an MTP call is received but MTP is not configured, transcoding is used if resources are available.

• Dynamic conference and transcoding resource allocation is not supported.

• Fax is not supported for transcoding.