In releases before Cisco IOS XE Cupertino 17.9.1w, On cBR-8 routers, the MSOs have the option to configure the upstream power
only at the upstream channel level on the RPD. Cisco RPD solution implements the total absolute power per channel calculated
with reference to 0dBmV/6.4 MHz. This means that the total power of the entire upstream channel is always constant irrespective
of the channel width and therefore the power spectral density of the channel decreases for larger channels.
In releases before Cisco IOS XE Cupertino 17.9.1w the implementation of upstream power for different channel widths is as
specified below:
For 1.6 MHz channel, power per 1.6MHz bandwidth is 0dBmV, total power is 0 dBmV
For 3.2 MHz channel, power per 1.6MHz bandwidth is -3dBmV, total power is 0 dBmV
For 6.4 MHz channel, power per 1.6MHz bandwidth is -6 dBmV, total power is 0 dBmV
(or)
For 1.6 MHz channel, power per 6.4MHz bandwidth is +6dBmV, total power is 0 dBmV
For 3.2 MHz channel, power per 6.4MHz bandwidth is +3dBmV, total power is 0 dBmV
Cable labs RPHY specification has an option to configure the upstream base port RF power in units of 0.1dBmV per 1.6Mhz RF
bandwidth.
cBR-8 routers support RPHY GCP TLV 98.3 - BaseTargetRxPower for the upstream controller port on the RPD. The base power config
can be applied to both cable upstream controller-profile
and cable rpd
level. If configured at both levels, the configuration at the cable rpd
level takes priority for that rpd.
At the RPD upstream port (service group) level, the Remote PHY standard allows a CCAP core to configure a base target power
reference level for all upstream signals from a given US RF port. This reference level is specified as a power spectral density
(dBmV per 1.6 MHz) through GCP TLV 98.3, which corresponds to UsRfPort.BaseTargetRxPower.
Use the base-power-rx-level-1_6Mhz option under cable upstream controller-profile to enable base power configuration for the entire upstream port.
router(config)#cable upstream controller-profile 499
router(config-controller-profile)#base-power-rx-level-1_6Mhz ?
<-20 - 40> Supported ranges: -15~24 for rphy-node, -15~20 for
rphy-shelf(ref pt:0dBmV/1.6Mhz)
Use the following command to disable TLV 98.3 on cBR-8: router(config-controller-profile)#no base-power-rx-level-1_6Mhz
The allowed range for upstream controller port base power configuration per CableLabs specification is -20 to +40 dBmV/1.6MHz.
Cisco RPD 1x2 supports only the following ranges for pga gain configuration: -9 to +30 dBmV/6.4MHz for rphy-node and -9 to
+26 dBmV/6.4MHz for rphy-shelf. Since there can be multiple RPDs per upstream controller port, you must pay attention to the
RPD-specific capabilities, to correctly configure the base port power values. The software does not restrict the configuration
to allow multiple RPD vendors using the same upstream controller profile. You can reconfigure the power levels at the per-channel
level appropriately.
The option to configure the base port power config at the profile level, affects all RPDs using that profile; while the configuration
at the cable rpd
level fine tunes the base power configuration only for that upstream port on that RPD. It also takes precedence over the
profile configuration for base power if present.
At the RPD level, use the base-power-rx-level-1_6Mhz option under cable rpd to enable base power configuration.
router(config)#cable rpd node1
router(config-rpd)#identifier aaaa.bbbb.cccc
router(config-rpd)#rpd-us 0 base-power-rx-level-1_6Mhz ?
<-20 -40> Supported ranges : -15~24 for rphy-node, -15~20 for rphy-shelf
(refpt:0dBmV/1.6Mhz)
Configuring the base power using either of the preceding commands, trigger the TLV 98.3 message from CBR8 to RPD and the implementation
on RPD changes to reflect new power calculations based on 0dBmV/1.6MHz reference.
Use the following command to disable TLV 98.3 on cBR-8: router (config-rpd)#no rpd-us 0 base-power-rx-level-1_6Mhz
. Use this option to configure US Base target power level in units of dBmV/1.6MHz (TLV 98.3).
Feature Name |
Release Information |
Feature Description |
Received power MIB Update for SCQAM and OFDMA channels
|
Cisco IOS XE Dublin 17.12.1y
|
In this release, the received power for all the upstream channels, SCQAM and OFDMA, will be reported in 1.6MHz reference.
It will also include upstream RF port basepower if configured (applicable to rphy only). The following MIBs has been updated:
|
In the release Cisco IOS XE Dublin 17.12.1y, on CBR8, the per CM MIB reporting upstream channel received power - docsIf3CmtsCmUsStatusRxPower
and docsIf31CmtsCmUsOfdmaChannelRxPower - will now report the received power of the SCQAM and OFDMA upstream channels respectively
at 1.6MHz PSD reference per the cable labs specification. This is applicable to all CMs online on both ICMTS and RPHY linecards.Also
both the MIBs now also include the base power, if configured on the RPHY upstream RF port along with the per channel power
level in the Received Power reporting. The upstream RF port base power feature was introduced for RPHY cards in IOS-XE 17.9.1y
release.
The implementation of upstream power for different channel widths is as specified below for the release Cisco IOS XE Dublin
17.12.1y:
CBR8#scm b42a.0e85.4339 verbose | i Received Power
Received Power Delta (dBmV) : 0.00 0.00 0.00 -0.25
Config Received Power(dBmV@chw) : -6.00 -3.00 0.00 0.00
Received Power(dBmV@chw) : -6.00 -3.00 0.00 -0.25
Config Received Power(dBmV@1.6MHz) : -6.00 -6.00 -6.00 -6.00
Received Power(dBmV@1.6MHz) : -6.00 -6.00 -6.00 -6.25
CBR8r#
SCQAM:
lwr-lnx-util-1:~ > snmpwalk -v 2c -c public 2.29.1.1 1.3.6.1.4.1.4491.2.1.20.1.4.1.3 | more
SNMPv2-SMI::enterprises.4491.2.1.20.1.4.1.3.4718593.494952 = INTEGER: -60
SNMPv2-SMI::enterprises.4491.2.1.20.1.4.1.3.4718593.494953 = INTEGER: -60
SNMPv2-SMI::enterprises.4491.2.1.20.1.4.1.3.4718593.494954 = INTEGER: -60
SNMPv2-SMI::enterprises.4491.2.1.20.1.4.1.3.4718595.494952 = INTEGER: -60
OFDMA: (Actual + config Received Power)
lwr-lnx-util-1:~ > snmpwalk -v 2c -c public 2.29.1.1 1.3.6.1.4.1.4491.2.1.28.1.4.1.1
SNMPv2-SMI::enterprises.4491.2.1.28.1.4.1.1.4718593.494955 = INTEGER: -62
SNMPv2-SMI::enterprises.4491.2.1.28.1.4.1.1.4718594.494955 = INTEGER: -60
Upstream Per-Channel TLVs
For the per-channel upstream power config, it captures either the total absolute power levels per 6.4MHz or true power adjust
levels depending on whether the upstream base power command base-power-rx-level-1_6Mhz
is configured. The per-channel command has enhanced help strings to display the changes if base-power-rx-level-1_6Mhz
is configured.
Router (config-controller-profile)#us-channel 0 power-level ?
<7 -25> Power level in dBmV-total power in units of dBmV per 6.4 Mhz if base-power-rx-level-1.6Mhz NOT configured (-x~y for rphy-node, x~y for rphy-shelf)
[OR] power adjust in units of dBmV per 1.6 Mhz if base-power-rx-level-1_6Mhz configured
Configuration With SC-QAM Upstream Channel
router(config)#cable upstream controller-profile 499
CBR8(config-controller-profile)#base-power-rx-level-1_6Mhz 10
CBR8(config-controller-profile)# us-channel 0 channel-width 3200000 3200000
CBR8(config-controller-profile)# us-channel 0 docsis-mode atdma
CBR8(config-controller-profile)# us-channel 0 power-level 5
Here us-channel 0 power-level 5
indicates US target rx power adjust level - true power adjust with above upstream base power config(TLV 65.9).
For the per-channel upstream power config, if the base port power level is configured via TLV 98.3, the channel adjusts automatically
become true channel adjusts in Cisco 1x2 RPD. You must reconfigure the per channel power adjust if needed by taking the new
port base power configuration into consideration.
NVGEN For cBR-8
All the upstream RF port base power configurations are nv-gened. The base power configuration is available in show running-configuration
once you enable it. The default configuration for the CBR8 is the no
version of the base power command for the TLV 98.3. If you do not enable the feature or explicitly disable the feature, then
the default configuration can be verified by using the no
version of this feature in show running-config all
.
For example, with no base power config on the upstream RF port, see the following sample outputs for the show run
and the show run all
:
Router#show run all | sec cable upstream controller-profile 3
cable upstream controller-profile 3
description Cox-upstream-prof-eg
no base-power-rx-level-1_6Mhz
cable def-phy-burst 0
us-channel 0 chan-class-id 7
us-channel 0 channel-width 6400000 6400000
<<!snip>
Router#show run | sec cable upstream controller-profile 3
cable upstream controller-profile 3
description Cox-upstream-prof-eg
us-channel 0 chan-class-id 7
us-channel 0 channel-width 6400000 6400000
us-channel 0 docsis-mode atdma
us-channel 0 equalization-coefficient
<<!snip>
Router#show run all | sec node1
cable rpd node1
description rpd-cbr8-4
identifier aaaa.bbbb.cccc
type node
<<!snip>>
no rpd-ds 1 mute
no rpd-ds 1 shutdown
no rpd-us 0 base-power-rx-level-1_6Mhz
no rpd-us 1 base-power-rx-level-1_6Mhz
<<!snip>>
Router#show run | sec node1
cable rpd node1
description TB17-RPD2-3 HWaddr F4:DB:E6:FE:CC:E2
identifier aaaa.bbbb.cccc
core-interface Hu9/1/8
principal
rpd-ds 0 downstream-cable 9/0/4 profile 25
rpd-us 0 upstream-cable 9/0/4 profile 3
rpd-us 1 upstream-cable 9/0/5 profile 3
r-dti 1
rpd-event profile 0
rpd-55d1-us-event profile 0
Sample CLI Configuration with TLV 98.3 for 0dBmV/6.4MHz
The folowing table shows examples of setting up the CLI to configure total absolute power level of 0dBmV/6.4Mhz (current
Cisco implementation) using the new CLI for base power config and corresponding TLV 98.3 sent to RPD.
Table 2.
Cisco IOS XE Version
|
CLI configuration on cBR-8
|
TLV 98.3 and TLV 65.9 sent to RPD
|
Description
|
Cisco IOS XE Cupertino 17.9.1w and later
|
router(config)#cable upstream controller-profile 499
router(config-controller-profile)#base-power-rx-level-1_6Mhz -6
router(config-controller-profile)#us-channel 0 channel-width 1600000 1600000
router(config-controller-profile)#us-channel 0 power-level 0
|
TLV 98.3 -> -60
TLV 65.9 -> 0
|
The base power value of -6 dbmV per 1.6Mhz translates 0 dbmV per 6.4Mhz and the channel power adjusts are true power adjusts
now. This config on BOTH RPD and CBR8 are aligned with cable lab spec power level definition.
|
Releases before Cisco IOS XE Cupertino 17.9.1w
|
router(config)#cable upstream controller-profile 499
router(config-controller-profile)#us-channel 0 channel-width 1600000 1600000
router(config-controller-profile)#us-channel 0 power-level 0
|
TLV 65.9 -> 0
|
This Cisco IOS XE version does not support tlv 98.3, so cBR-8 and cisco rpd config are aligned with current legacy implementation.
|