| Description | This attribute when set to 'true' triggers the change-over
operation for Externally-Directed Load Balancing.
Setting this attribute to 'true' is known as a commit
operation. A commit operation is considered successful
if the CMTS considers that the entered information
is valid and the transaction can be initiated. It
does not imply that the channel-change operation itself
(i.e. UCC, DCC, DBC transaction) reports success
or completion. A commit operation is considered unsuccessful
if the CMTS determines that there are invalid
attributes values in the ChangeOver object such
that the change-over operation cannot be initiated.
After system initialization all ChangeOver object
parameters are set to default values.
After a successful commit operation all ChangeOver
object parameters are set to default values with the
exception of this attribute (commit) that is set to 'true'.
An unsuccessful commit operation is rejected
and this attribute reports false in subsequent value
queries.
With regard to error checking on a commit operation,
the following aspects are defined:
- The CMTS rejects the commit operation when the MAC address
in MacAddr attribute is not from an existing and
operational cable modem in the CMTS.
- The CMTS rejects the commit operation when there is
already a change-over operation in progress for the
CM, i.e. the corresponding attribute value in the -ChangeOverStatus
object is one of 'messageSent', 'modemDeparting'
or 'waitToSendMessage'.
- The CMTS rejects the commit operation when neither
of the upstream or downstream attribute parameters
of the change-over operation are set.
When the CM is in MRC disabled mode, only UCC/DCC commands
are valid, therefore:
- The CMTS ignores the values of RcpId, RccId, and ServiceFlowInfo
in the commit operation.
- The CMTS rejects the commit operation if neither of
DownFrequency or UsChSet were set to non-default values.
- The CMTS rejects the commit operation when the UsChSet
indicates more than one upstream channel.
- A single-upstream-channel change-over operation
(no downstream information) is rejected if the upstream
channel information corresponds to a non-existent
channel or a channel with operational status down.
- The CMTS rejects the commit operation for a downstream
frequency that the CMTS can determine to be invalid.
For example, the downstream frequency corresponds
to a channel that is part of the MD-DS-SG in which the
target CM is currently registered, and this Downstream
Channel is known to be operationally down, in a
test mode, mute state, etc.
- To move a MRC/MTC-capable CM to a MRC/MTC enabled MAC
Domain, the operator needs to reinitialize the CM via
a DCC operation by including the appropriate DownFrequency
and an InitTech allowing only the 'reinitialize
MAC' initialization technique.
When the CM is in MRC enabled mode, DCC and DBC commands
are valid, therefore:
- The CMTS rejects the commit operation if both the Downstream
Frequency (via the DownFrequency attribute)
and the RCC (via the RcpId and RccId) are set to non-default
values.
- The CMTS rejects the commit operation if the MdIfIndex
attribute value is invalid, or if the triplet MdIfIndex,
RcpId, RccId does not resolve in a valid RCC,
or at least one of the indicated downstream channels
is know to be operationally down, in a test mode, mute
state, etc.
- The CMTS rejects the commit operation if it can detect
the UsChSet includes one or more channels that are
not part of the US-SG of the CM, or any of those channels
are in operational status down.
- The CMTS rejects the commit operation if a service flow
entry in the ServiceFlowInfo attribute includes
channels that are not part of the CMs target RCS or TCS.
After processing the commit operation the CMTS creates
or overwrites (if it already exists) an instance
of the ChgOverStatus object for the associated CM.
After a successful commit operation, the CMTS initiates
the change-over transaction using the most appropriate
technique. The potential techniques are:
- UCC - For upstream-channel-only changes on CMs not
operating in MRC mode.
- DCC - For upstream and/or downstream channel changes
on CMs not operating in MRC mode.
- DCC followed by channel assignment in REG-RSP-MP -
For MAC Domain re-assignment on CMs operating in MRC
mode. In this case, the change-over command might only
include a downstream frequency, or might include
an RCC defined in the target MAC domain. The upstream
channel set may or may not be provided. The only applicable
Initialization Technique for this operation
is 'reinitializeMAC'.
- DBC - For upstream and/or downstream channel set changes
on CMs operating in MRC mode. |