Cisco Headend System Release 2.7 Design Guide
DNCS Configuration for SFM
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The DHCT does not have prior knowledge of the DSG tunnel address when it is
searching for the appropriate DOCSIS downstream. Instead, the DHCT parses the
DCD message and determines which, if any, Cisco DSG clients (client IDs) are listed
in the DCD message. If the required client IDs are listed in the DCD message, the
DHCT will remain on the DSG channel to receive the out-of-band data. If the
required client IDs are not listed in the DCD message, the DHCT will continue
searching for out-of-band data.
searching for the appropriate DOCSIS downstream. Instead, the DHCT parses the
DCD message and determines which, if any, Cisco DSG clients (client IDs) are listed
in the DCD message. If the required client IDs are listed in the DCD message, the
DHCT will remain on the DSG channel to receive the out-of-band data. If the
required client IDs are not listed in the DCD message, the DHCT will continue
searching for out-of-band data.
CMTS Global Configuration in a Non-Straddle Environment
A "non-straddle environment" is defined as a single DOCSIS RF downstream that
covers the DHCT populations that are served by the same hub. The system operator
should configure the following criteria in a non-straddle environment:
covers the DHCT populations that are served by the same hub. The system operator
should configure the following criteria in a non-straddle environment:
DSG tunnels with their respective MAC address
DSG classifiers that allow the CMTS to route traffic to the appropriate DSG
tunnel
tunnel
Client lists that are used by the DHCT to pick rules that apply to it
CMTS Interface Configuration
Each interface on the CMTS device that receives multicast traffic must have several
customized configurations. These configurations must specifically address the
following two scenarios for configuring the CMTS:
customized configurations. These configurations must specifically address the
following two scenarios for configuring the CMTS:
Non-Hub Straddling (on page 10)
Hub Straddling (Regionalization) (on page 14)
The general IP multicast CMTS configurations include the following scenarios:
Each interface that receives multicast traffic must be enabled with Protocol
Independent Multicast (PIM).
Independent Multicast (PIM).
RF Interfaces that forward multicast traffic must be statically configured using
the CMTS to join the Cisco out-of-band multicast groups defined on the DNCS.
Note: Some Internetwork Operating Systems (IOS), for example, Cisco,
automatically include the "ip igmp static" command when the "cable
downstream DSG Rule" is configured. If this occurs for your CMTS, configuring
the "ip igmp static" command will not be necessary.
the CMTS to join the Cisco out-of-band multicast groups defined on the DNCS.
Note: Some Internetwork Operating Systems (IOS), for example, Cisco,
automatically include the "ip igmp static" command when the "cable
downstream DSG Rule" is configured. If this occurs for your CMTS, configuring
the "ip igmp static" command will not be necessary.
DSG Rules should be configured on the downstreams to which they apply. This
will result in a different DCD message sent from each downstream.
will result in a different DCD message sent from each downstream.
The configuration of a DSG "Classifier" is required. The DSG Classifier enables
the DSG agent to map the IP multicast address to the DSG tunnel. If ports are not
included in the DSG classifier or if the DSG classifier is not included in the DCD
message, the set-top will filter the Cisco DSG data based on existing, well-known
port numbers.
the DSG agent to map the IP multicast address to the DSG tunnel. If ports are not
included in the DSG classifier or if the DSG classifier is not included in the DCD
message, the set-top will filter the Cisco DSG data based on existing, well-known
port numbers.