Cisco GoQAM Installation And Operation Manual page 25

Stage Description
5 The clear and encrypted streams are synchronized.
6 An overlay output stream is created by muxing (multiplexing) the clear,
S-A encrypted, and third-party encrypted packets.
7 The output stream is modulated at 64 QAM or 256 QAM and sent out one
of the two IF ports.
4004834 Rev D
Input/Output Process
9