Chapter 14: Cable-side Configuration
STANDARD Revision 1.0
C4® CMTS Release 8.3 User Guide
© 2016 ARRIS Enterprises LLC. All Rights Reserved.
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Term
Definition
An MD-CM-SG differs from a CM-SG only if multiple MAC domains are represented in the
same CM-SG. The C4/c CMTS will attempt to identify the MD-CM-SG identifier for each
cable modem as it initializes.
MD-CM-SGs are calculated automatically by the C4/c CMTS based on the channel-to-fiber-
node and channel-to-MAC-domain provisioning.
MAC Domain
Downstream Service
Group (MD-DS-SG)
The subset of downstream channels from an MD-CM-SG is a MAC domain downstream
service group (MD-DS-SG). The downstream channels of a MD-DS-SG may be replicated
(via RF splitter devices) across multiple MD-CM-SGs. In this case the MD-DS-SG is said to
be a part of multiple MD-CM-SGs.
The determination of the MD-DS-SG by the cable modem during a CM initialization is an
important part of identifying the MD-CM-SG of a CM.
MD-DS-SGs are calculated automatically by the C4/c CMTS based on the channel-to-fiber-
node and channel-to-MAC-domain provisioning.
MAC Domain
Upstream Service
Group (MD-US-SG)
The subset of upstream channels from an MD-CM-SG is known as a MAC domain
upstream service group (MD-US-SG).
The upstream channels of a MD-US-SG may be shared (via RF combiner devices) across
multiple MD-CM-SGs. In this case the MD-US-SG is said to be a part of multiple MD-CM-
SGs.
The determination of the MD-US-SG by the C4/c CMTS during a CM initialization is an
important part of identifying the MD-CM-SG of a CM. MD-US-SGs are calculated (as read-
only data) by the C4/c CMTS from the channel-to-fiber-node and channel-to-MAC-domain
provisioning.
Once the sets of downstream channels and logical upstream channels that reach each
MD-CM-SG have been determined, the C4/c CMTS will use this information to assign the
proper channels to each cable modem.
