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D3 modems load balancing multiple interface cards

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pzoli1
D3 modems load balancing multiple interface cards

HI.
I have a ubr10k cmts (122-33.SCF5) with mc20x20 cards.
My idea: Interface cards: 5/1 - active; 6/1 "active redundancy".

The load balancing is works only D2 modems.
D3 modems: the primary ds always 5/1/x.

Config:
!
cable load-balance docsis-group 5100 index 81
downstream Integrated-Cable 5/1/0 rf-channel 0-3
downstream Integrated-Cable 6/1/0 rf-channel 0-3
upstream Cable5/1/0 0-3
upstream Cable6/1/0 0-3
threshold load 5
policy pure-ds-load
init-tech-list 0
!
cable fiber-node 1
downstream Integrated-Cable 5/1/0 rf-channel 0-3
upstream Cable 5/1 connector 0-3
!
cable fiber-node 2
downstream Integrated-Cable 6/1/0 rf-channel 0-3
upstream Cable 6/1 connector 0-3
!

kwesibrunee
You have 2 problems

This is your first problem,

from this document http://www.cisco.com/c/en/us/td/docs/interfaces_modules/cable/broadband_...

Restrictions for Configuring the Cisco UBR-MC20X20V Cable Interface Line Card

•A bonded channel must be made up of channels only from the local card and not from multiple cable line cards.

your second problem is you need to configure Docsis 3.0 load balancing separate from Docsis 1.x/2.0, the cable load-balance docsis-group 5100 style is for D1.x and D2.0 modems.

the cable load-balance docsis-group FN 1 MD Cable5/1/0 style are for docsis 3.0 modems, if you look at the running config with the all setting i.e, show running-config all you will see they are already setup and ready to go with defaults, but you still won't be able to load balance across line cards.

pzoli1
dcc initialization techniques 0

I knew this problems, but i read in http://www.cisco.com/c/en/us/td/docs/cable/cmts/config_guide/b_cmts_ds_u...

For load balancing between cards (inter-card), DCC initialization technique 0 will be used in all cases, regardless of what technique is set for the LB group or what card types are used.

For load balancing between multiple cable interface line cards (inter-card implementation), DCC initialization technique 0 is to be used in all cases, regardless of what technique is set for the load balancing group or which cable interface line card types are used.

May this be out of order?

pzoli1
resolution

I make an expect script:
- shutdown wideband interface on the actual cable interface
- clear wideband modems on the actual cable interface
- old wideband modems going to other cable interface than D2 modems (D2 load balance or manual)
- start wideband interface (if cable wideband auto-reset active, all ok)

This script running, if too big the difference of two cable interface. (1-2 weeks)
The disadvantage of the solution: two wideband modem reset per 1-2 weeks. (clear and auto-reset)

mbowe
Is the config you posted just

Is the config you posted just a fragment/example, or do you only have the 2 fiber nodes on your system ?

Regardless, I would restructure the wiring so that each node is fed only from 1 linecard.

You could retain the same amount of capacity (eg 8DS) but you will also gain :
* working D3 load-balance
* 8-way bonding if you want it
* ability to scale up further to eg 12 or 16DS

If you need line redundancy then grab a pair of Cisco 3x10 RF switches (cheap on ebay) and configure 1 x 2020 card to be a hotspare/protect. You can protect up to 7 x 2020 cards with a single hotspare.

I wrote up some other 20x20 design tips here in case you need ideas :
http://www.docsis.org/comment/5866#comment-5866

pzoli1
The config

The config is just a fragment.
There are 10 fiber node. 2 x 20x20 cards (5/0,5/1), 4ds+4us per node.

And 2 x 20x20 cards (6/0,6/1) that i would like active redundant.
If all card ok, the secondary 2 x 20x20 cards (6/0,6/1) relieves.
In case of a mistake 5/0 - 6/0 and 5/1 - 6/1 are redundant.

I know ubr10012 does not know this.
i restructure wiring only in case of emergency.

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