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Cisco Broadband Cable Command Reference Guide
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Chapter 2 Cisco CMTS Configuration Commands
cable service class
Defaults
Values that are not specified are set to their DOCSIS 1.1 defaults, if applicable to the service-class
schedule type. See Section C.2.2,
Service Flow Encodings
, in the DOCSIS 1.1 specification.
Command Modes
Global configuration
Command History
Usage Guidelines
The
sched-type
option must always be specified for each class. When a certain scheduling type is
selected, take care that the mandatory parameters for that scheduling type are explicitly entered, while
nonapplicable parameters must be explicitly removed.
The default direction is
upstream
. We recommend that you do not change the direction of a service class
after you have created it, because some of the existing service class parameters might not be appropriate
for the new direction. Instead, delete the current service class and create a new service class with the
correct upstream or downstream direction.
If the service class is newly created, a service-class name must be defined before entering the parameters
for the service class.
Note
Section C.2.2.6.10,
IP Type of Service Overwrite
, of the DOCSIS 1.1 specification changed the operation
of
tos-overwrite
option. In DOCSIS 1.1 networks, the new TOS value is calculated by the following
formula: New IP TOS = ((Original TOS value AND
and-mask
) OR
or-mask
). (For a description of the
previous method of calculating the TOS value, see the
cable qos profile
command.) The default is to
leave the TOS value unchanged (no overwrite).
tos-overwrite
and-
mask
or-mask
Overwrites the ToS byte by first ANDing the TOS value with the
and-mask
value and then ORing the result of that operation with the
or-mask
value.
Both parameters must be specified in hexadecimal. The
and-mask
value can
range from 0x0 to 0xFF and the
or-mask
value can range from 0x0 to 0xFF.
upstream
Specifies that the service class is for the upstream direction (from the CM
to the CMTS). This is the default direction.
Release
Modification
12.1(4)CX
This command was introduced for DOCSIS 1.1 operation. This command
replaced the
cable qos profile
command that was used in previous versions
for DOCSIS 1.0 operation.
12.2(4)BC1
Support for this command was added to the Release 12.2 BC train. This
command was also enhanced to support NRTPS scheduling.
12.2(11)BC2
The default value for the maximum transmission burst parameter (max-
burst) was changed from 1522 bytes to 3044 bytes. The default value for the
maximum concatenation burst parameter was also changed from 0 bytes
(unlimited) to 1522 bytes. These changes are to accommodate the latest
revision of the DOCSIS 1.1 specification (SP-RFI-v1.1-I09-020830).