# Using RTP multiple unicast connections

RTP multiple unicast connections enable applications to transfer an encoded simplex stream of voice data (through a simplex voice encoder channel) to multiple RTP simplex endpoints. Applications can connect up to eight RTP simplex endpoints to one DS0 endpoint through a single simplex voice encoder channel.

The following illustration shows an RTP multiple unicast connection:

Applications create RTP multiple unicast connections in the following way:

Step | Action
1 | Create the required number of RTP simplex send (MSP_ENDPOINT_RTPOUT or MSP_ENDPOINT_RTPOUT_V6) endpoints with mspCreateEndpoint.
2 | Create a single DS0 endpoint with mspCreateEndpoint.
3 | Create a single simplex voice encoder channel with mspCreateChannel.
4 | Invoke mspConnect once for each RTP simplex endpoint, specifying the same simplex encoder channel created in Step 3, and the same DS0 endpoint created in Step 2.
5 | Enable simplex encoder channel with mspEnableChannel.

To dismantle an RTP multiple unicast connection, disable the encoder channel with mspDisableChannel. Then invoke mspDisconnect for each RTP simplex send endpoint before destroying the associated DS0 endpoint, the RTP endpoints, or the encoder channel.