Cisco DNCS System Release 2.8.1 3.8.1 4.3.1 User Guide

If you are using an RF GoQAM modulator to send content to DHCTs and you have already added an MPEG source
to the DNCS database, you are ready to add the RF GoQAM modulator to the DNCS database. 

RF GoQAMs are a critical component of our Overlay solution. Overlay technology allows cable service providers to
support DHCTs manufactured by us and by other vendors. RF GoQAM modulators can receive both clear and
encrypted program and service data, such as, audio/video programming and Web services. They filter, modify,
synchronize, and combine the two data streams into a single transport stream and send this stream to hubs.
Once processed by the RF GoQAM, the transport stream can be used by DHCTs from different manufacturers,
without regard to the type of encryption method that each DHCT uses. 

Important: If you do not use Overlay technology, do not add an RF GoQAM modulator to your DBDS. Adding an
RF GoQAM modulator in a system that does not use Overlay technology can cause your system to behave
unpredictably.

Before you begin, you must have your network map. You must also have the following information:



Name of the headend containing the RF GoQAM modulator



Name used to identify the RF GoQAM modulator



IP address for the RF GoQAM modulator (from your system administrator)



Type of modulation standard the RF GoQAM modulator uses, such as ITU J.83 Annex B



MAC address for the RF GoQAM modulator



Subnet mask for the RF GoQAM modulator (from your system administrator)



If applicable, the default gateway that the RF GoQAM modulator uses



Numbers identifying the input pairs that physically connect the modulator to the associated MPEG

sources.



The type of QAM used, such as 256 QAM or 64 QAM.



Numbers identifying the transport streams going from the RF GoQAM modulator out to the hubs on

your system



Frequencies of the channels being used to send data from the RF GoQAM modulator to the hubs on

your system



Names of the hubs you want to receive data from this RF GoQAM modulator



Name of the headend containing the MPEG sources that send content data to this RF GoQAM

modulator



Type of MPEG source devices being used to send data to this RF GoQAM modulator (for example, IRT,

MDR, VOD server, and so forth)



Names of the associated MPEG sources



Numbers identifying the output ports of the associated MPEG sources that are physically connected to

the input ports on this RF GoQAM modulator



All of this information should be recorded on your network map. However, if it is not, contact your