Cisco Headend System Release 2.7 기술 참조
738184 Rev B
OCAP System Implementation
2-3
SR 4.0 System Support,
Continued
DOCSIS Set-Top Gateway
The DOCSIS Set-Top Gateway (DSG) data delivery method is derived from a
The DOCSIS Set-Top Gateway (DSG) data delivery method is derived from a
CableLabs specification that describes how the Cable Modem Termination System
(CMTS) forwards broadcast OOB data to OpenCable hosts.
Note: For more information, refer to the DOCSIS
Note: For more information, refer to the DOCSIS
®
Set-top Gateway (DSG) Interface
Specification, CM-SP-DSG-I03-041124 (Available from CableLabs).
DSG allows cable operators to move the CableCARD module’s QPSK OOB
DSG allows cable operators to move the CableCARD module’s QPSK OOB
downstream signaling to the DOCSIS channel. The headend uses the OOB signal to
send encryption and authorization signals down to the CableCARD module.
Specifically, the DSG OOB signal transmits from the headend to a cable modem
termination system (CMTS). From the CMTS, the OOB signal is transmitted to an
OpenCable host containing an embedded DOCSIS cable modem. The host forwards
the OOB data to the CableCARD module.
With DSG, OOB data flows from the DNCS to one or multiple IP addresses. Cable
With DSG, OOB data flows from the DNCS to one or multiple IP addresses. Cable
operators are responsible for defining the MAC addresses. The hosts dynamically
learn the MAC addresses through a downstream channel detector (DCD) message.