Cisco 7246VXR - uBR Router Software Configuration Manual page 73

Chapter 1 Overview of Cisco uBR7200 Series Software
The following example of the show cable qos profile command illustrates that the maximum
downstream burst has been defined, and is a management-created QoS profile:
Router# show cable qos pro
ID
1
2
3
4
6
10
50
51
The following example illustrates the maximum downstream burst size in sample QoS profile 10 with
the show cable qos prof verbose command in privileged EXEC mode:
Router# show cable qos pro 10 ver
Profile Index
Name
Upstream Traffic Priority
Upstream Maximum Rate (bps)
Upstream Guaranteed Rate (bps)
Unsolicited Grant Size (bytes)
Unsolicited Grant Interval (usecs)
Upstream Maximum Transmit Burst (bytes) 1522
Downstreamam Maximum Transmit Burst (bytes) 100000
IP Type of Service Overwrite Mask
IP Type of Service Overwrite Value
Downstream Maximum Rate (bps)
Created By
Baseline Privacy Enabled
Usage Guidelines
If a cable modem registers with a QoS profile that matches one of the existing QoS profiles on the Cisco
CMTS, then the maximum downstream burst size, as defined for that profile, is used instead of the
default DOCSIS QoS profile of 1522.
For example, a DOCSIS 1.0 configuration that matches QoS profile 10 in the previous examples would
be as follows:
03 (Net Access Control)
04 (Class of Service Encodings Block)
The maximum downstream burst size (as well as the ToS overwrite values) are not explicitly defined in
the QoS configuration file because they are not defined in DOCSIS. However, because all other
parameters are a perfect match to profile 10 in this example, then any cable modem that registers with
these QoS parameters has a maximum downstream burst of 100000 bytes applied to it.
For further illustration, consider a scenario in which packets are set in lengths of 1000 bytes at 100
packets per second (pps). Therefore, the total rate is a multiplied total of 1000, 100, and 8, or 800kbps.
OL-2239-05
Prio Max Guarantee Max
upstream upstream
bandwidth bandwidth bandwidth
0 0 0
0 64000 0
7 31200 31200
7 87200 87200
1 90000 0
1 90000 0
0 0 0
0 0 0
S01 (Class ID)
S02 (Maximum DS rate)
S03 (Maximum US rate)
S06 (US burst)
S04 (US Channel Priority)
S07 (Privacy Enable)
Cisco uBR7200 Series Universal Broadband Router Software Configuration Guide
Supported Software Features for the Cisco uBR7200 Series
Max TOS TOS
downstream tx mask value by
burst
0 0 0xFF 0x0
1000000 0 0xFF 0x0
0 0 0xFF 0x0
0 0 0xFF 0x0
90000 1522 0xFF 0x0
90000 1522 0x1 0xA0
96000 0 0xFF 0x0
97000 0 0xFF 0x0
10
1
90000
0
0
0
0x1
0xA0
90000
mgmt
no
= 1
= 1
= 90000
= 90000
= 1522
= 1
= 0
Create B IP prec.
priv rate
enab enab
cmts(r) no no
cmts(r) no no
cmts yes no
cmts yes no
mgmt yes no
mgmt no no
mgmt no no
mgmt no no
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