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Traffic not balanced between wideband interfaces - Ubr10k

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assafk
Traffic not balanced between wideband interfaces - Ubr10k

Hi,

We have segments with 20 DS channels and with 4 WB groups which configured as listed below.
all DS are primary channels and spread across multiple mac-domains

interface Wideband-Cable5/0/0:0
load-interval 30
cable bundle 1
cable rf-channel 0 bandwidth-percent 1
cable rf-channel 1 bandwidth-percent 1
cable rf-channel 2 bandwidth-percent 1
cable rf-channel 3 bandwidth-percent 1
cable rf-channel 4 bandwidth-percent 1
cable rf-channel 5 bandwidth-percent 1
cable rf-channel 6 bandwidth-percent 1
cable rf-channel 7 bandwidth-percent 1

interface Wideband-Cable5/0/0:1
load-interval 30
cable bundle 1
cable rf-channel 8 bandwidth-percent 1
cable rf-channel 9 bandwidth-percent 1
cable rf-channel 10 bandwidth-percent 1
cable rf-channel 11 bandwidth-percent 1
cable rf-channel 12 bandwidth-percent 1
cable rf-channel 13 bandwidth-percent 1
cable rf-channel 14 bandwidth-percent 1
cable rf-channel 15 bandwidth-percent 1

interface Wideband-Cable5/0/0:2
load-interval 30
cable bundle 1
cable rf-channel 12 bandwidth-percent 1
cable rf-channel 13 bandwidth-percent 1
cable rf-channel 14 bandwidth-percent 1
cable rf-channel 15 bandwidth-percent 1
cable rf-channel 16 bandwidth-percent 1
cable rf-channel 17 bandwidth-percent 1
cable rf-channel 18 bandwidth-percent 1
cable rf-channel 19 bandwidth-percent 1

and additional WB group with all the 20 rf-channels.

we are facing a strange phenomenon where the DOCSIS3.0 cable modems are not being balanced correctly.
Most of the DOCSIS3.0 cable modems are being locked on the first WB group.

show cable mac-domain cable 5/0/0 rcc
RCC-ID RCP RCs MD-DS-SG CMs WB/RCC-TMPL
1 00 00 00 00 00 8 0 75 WB (Wi5/0/0:0)
2 00 00 00 00 00 8 0 31 WB (Wi5/0/0:1)
3 00 00 00 00 00 8 0 29 WB (Wi5/0/0:2)
4 00 00 00 00 00 20 0 1 WB (Wi5/0/0:3)

show cable mac-domain cable 5/0/1 rcc
RCC-ID RCP RCs MD-DS-SG CMs WB/RCC-TMPL
1 00 00 00 00 00 8 0 87 WB (Wi5/0/0:0)
2 00 00 00 00 00 8 0 27 WB (Wi5/0/0:1)
3 00 00 00 00 00 8 0 47 WB (Wi5/0/0:2)
4 00 00 00 00 00 20 0 1 WB (Wi5/0/0:3)

due to the mentioned above we are facing unequaled traffic across the WB interfaces.
interface Wi5/0/0:0 is much more loaded.

attached you can find utilization graphs and the load balancing and fiber-node configuration.

has someone faced a similar behavior and solve it?

Thanks in advance,
Asaf

Lopez
Try this

Try this
cable fiber-node 9
description interface Cable5/0/0
downstream Modular-Cable 5/0/0 rf-channel 0-19
upstream Cable 5/0 connector 0-3

cable load-balance rule 10 enabled
cable load-balance docsis-policy 10 rule 10

cable load-balance docsis-group FN 9 MD Cable5/0/0
no disable
method modems us-method modems
threshold load 10
threshold load minimum 5
threshold stability 50
threshold ugs 70
threshold pcmm 70
no policy ugs
no policy pcmm
no policy us-across-ds
no policy pure-ds-load
init-tech-list 4
docsis-policy 10
interval 30

Add "CMLoadBalancingPolicyID 10" to config file, and you have to restart all cm on this fiber node and check
sh cab modem c5/0/0 ver | i LB

assafk
Try this

Hi,

Can you please emphasize a bit regarding the rule you and policy you configured?
What should this rule should do?

Regarding your fiber-node we are working in a template which every connector gets it own fiber-node...

Thanks,
Asaf

mbowe
Some feedback

Just checking I understand your design :

1/ Modular-cable 5/0/0 DS channels 0-19 are feeding to an 6-way optical or coax splitter. So nodes 1-6 are seeing the same set of DS channels.
2/ Nodes 1 to 6 each come back to their own upstream connectors on linecard 5/0
3/ Nodes 1-2 are configured on mac-domain 5/0/0, nodes 3-4 on 5/0/1, nodes 5-6 on 5/0/2

If above is correct then the descriptions in your fiber-node stanzas seem to be wrong.
Probably should be :

cable fiber-node 1
description interface Cable5/0/0
cable fiber-node 2
description interface Cable5/0/0
cable fiber-node 3
description interface Cable5/0/1
cable fiber-node 4
description interface Cable5/0/1
cable fiber-node 5
description interface Cable5/0/2
cable fiber-node 6
description interface Cable5/0/2

Other than that, nothing obvious jumps at me as invalid in your config. But its hard to tell as you have only supplied a few fragments.

Are the modular channels contiguous frequency?

Does the modem distribution problem improve if you activate docsis 2.0 load balance?
(Below assumes you have activated 3 x US per node...)

cable load-balance docsis-group 5000
downstream modular-cable 5/0/0 rf-channel 0-2
downstream modular-cable 5/0/0 rf-channel 8-9
downstream modular-cable 5/0/0 rf-channel 16-17
upstream cable 5/0/0 0-2

cable load-balance docsis-group 5001
downstream modular-cable 5/0/0 rf-channel 0-2
downstream modular-cable 5/0/0 rf-channel 8-9
downstream modular-cable 5/0/0 rf-channel 16-17
upstream cable 5/0/0 3-5

cable load-balance docsis-group 5010
downstream modular-cable 5/0/0 rf-channel 3-5
downstream modular-cable 5/0/0 rf-channel 10-12
downstream modular-cable 5/0/0 rf-channel 18
upstream cable 5/0/1 0-2

cable load-balance docsis-group 5011
downstream modular-cable 5/0/0 rf-channel 3-5
downstream modular-cable 5/0/0 rf-channel 10-12
downstream modular-cable 5/0/0 rf-channel 18
upstream cable 5/0/1 3-5

cable load-balance docsis-group 5020
downstream modular-cable 5/0/0 rf-channel 6-7
downstream modular-cable 5/0/0 rf-channel 13-15
downstream modular-cable 5/0/0 rf-channel 19
upstream cable 5/0/2 0-2

cable load-balance docsis-group 5021
downstream modular-cable 5/0/0 rf-channel 6-7
downstream modular-cable 5/0/0 rf-channel 13-15
downstream modular-cable 5/0/0 rf-channel 19
upstream cable 5/0/2 3-5

Not related to load-balance, but more of a general efficiency point :
Do you really need to have every channel primary?
There is quite a bit of overhead / waste for each primary.
Reducing the number of primary channels save you bandwidth.
Eg if you had few D1.1 / 2.0 modems, then you could reduce it to something like 1 in 8 eg :
* 5/0/0 could have primary 0,8,16
* 5/0/1 could have primary 1,9,17
* 5/0/2 could have primary 2,10,18

assafk
Traffic not balanced between wideband interfaces - Ubr10k

Hi,

sorry for the late response....
first of all you understood the design perfectly.

the docsis2.0 load balancing is enabled as well and being configure by d20-ggrp-default settings.

regarding the modular channels contiguously please find below

rf-channel 0 frequency 111000000
rf-channel 1 frequency 117000000
rf-channel 2 frequency 129000000
rf-channel 3 frequency 135000000
rf-channel 4 frequency 141000000
rf-channel 5 frequency 147000000
rf-channel 6 frequency 153000000
rf-channel 7 frequency 159000000

rf-channel 8 frequency 177000000
rf-channel 9 frequency 183000000
rf-channel 10 frequency 189000000
rf-channel 11 frequency 195000000
rf-channel 12 frequency 201000000
rf-channel 13 frequency 207000000
rf-channel 14 frequency 213000000
rf-channel 15 frequency 219000000
rf-channel 16 frequency 225000000
rf-channel 17 frequency 231000000
rf-channel 18 frequency 237000000
rf-channel 19 frequency 249000000

meaning that for each wideband group of 8 DS channels the frequencies are contiguous.

Regards,
Asaf

oss-iris
Hello

Hello
What is the behavior of docsis 1/2 modems ?
Number of narrow frequencies is the same for all the downstreams?
There is maybe a priority for Narrow repartition against wideband?