Cisco Headend System Release 2.5 Design Guide
4
4042275 Rev A
Understand Direct ADSG
Understand Direct ADSG
This section provides an overview of a direct ADSG environment. It includes various
concepts and other information to help you understand how to provision direct
ADSG and CMTS bridge definitions on the DNCS.
concepts and other information to help you understand how to provision direct
ADSG and CMTS bridge definitions on the DNCS.
Broadcast Data Flow in a Direct ADSG Environment
In direct ADSG, the CableCARD module parses the downstream channel descriptor
(DCD) file which results in a DSG directory. This directory defines the broadcast
tunnels (IP addresses and ports) for each broadcast tunnel type. The embedded cable
modem (eCM) uses these broadcast tunnels to transmit broadcast DSG messages (SI,
EAS, XAIT, and CDL CVT) directly to an ADSG-compliant host device.
Note: For non-broadcast tunnel data (for example, passthru, BFS), the eCM uses the
extended channel to pass the DSG flows to the CableCARD module, which then uses
the command channel for delivery of the data to the host device.
The logical flow of broadcast tunnel data in an ADSG environment is shown in the
following diagram.
(DCD) file which results in a DSG directory. This directory defines the broadcast
tunnels (IP addresses and ports) for each broadcast tunnel type. The embedded cable
modem (eCM) uses these broadcast tunnels to transmit broadcast DSG messages (SI,
EAS, XAIT, and CDL CVT) directly to an ADSG-compliant host device.
Note: For non-broadcast tunnel data (for example, passthru, BFS), the eCM uses the
extended channel to pass the DSG flows to the CableCARD module, which then uses
the command channel for delivery of the data to the host device.
The logical flow of broadcast tunnel data in an ADSG environment is shown in the
following diagram.