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Ideal Dynamic Bandwidth Sharing settings

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Capm
Ideal Dynamic Bandwidth Sharing settings

I'm curious what kind of settings other people are running. Assuming a mix of D2 and 3 modems (8 and 4 channel versions), Do you find a certain percentage of allocation working better or worse? My understanding is that, out of 100% of a channel capacity, you can allocate a % to be dedicated to that channel, and the rest can be shared, same for each channel in each wideband interface. So is it better to staticly assign the least amount to each channel, or does that cause excessive load balancing of the d2 modems? Whats your experience?

----
interface Wideband-Cable1/0:0
cable bundle 1
cable rf-channel 0 bandwidth-percent 20 remaining ratio 100
cable rf-channel 1 bandwidth-percent 20 remaining ratio 100
cable rf-channel 2 bandwidth-percent 20 remaining ratio 100
cable rf-channel 3 bandwidth-percent 20 remaining ratio 100
cable rf-channel controller 1 channel 0 bandwidth-percent 20 remaining ratio 100
cable rf-channel controller 1 channel 1 bandwidth-percent 20 remaining ratio 100
cable rf-channel controller 1 channel 2 bandwidth-percent 20 remaining ratio 100
cable rf-channel controller 1 channel 3 bandwidth-percent 20 remaining ratio 100
!
interface Wideband-Cable1/0:1
cable bundle 1
cable rf-channel 0 bandwidth-percent 20 remaining ratio 100
cable rf-channel 1 bandwidth-percent 20 remaining ratio 100
cable rf-channel 2 bandwidth-percent 20 remaining ratio 100
cable rf-channel 3 bandwidth-percent 20 remaining ratio 100
!
interface Wideband-Cable1/0:2
cable bundle 1
cable rf-channel controller 1 channel 0 bandwidth-percent 20 remaining ratio 100
cable rf-channel controller 1 channel 1 bandwidth-percent 20 remaining ratio 100
cable rf-channel controller 1 channel 2 bandwidth-percent 20 remaining ratio 100
cable rf-channel controller 1 channel 3 bandwidth-percent 20 remaining ratio 100
!
interface Integrated-Cable1/0:0
cable bundle 1
cable rf-bandwidth-percent 20 remaining ratio 100
!
interface Integrated-Cable1/0:1
cable bundle 1
cable rf-bandwidth-percent 20 remaining ratio 100
!
interface Integrated-Cable1/0:2
cable bundle 1
cable rf-bandwidth-percent 20 remaining ratio 100
!
interface Integrated-Cable1/0:3
cable bundle 1
cable rf-bandwidth-percent 20 remaining ratio 100
!
interface Integrated-Cable1/1:0
cable bundle 1
cable rf-bandwidth-percent 20 remaining ratio 100
!
interface Integrated-Cable1/1:1
cable bundle 1
cable rf-bandwidth-percent 20 remaining ratio 100
!
interface Integrated-Cable1/1:2
cable bundle 1
cable rf-bandwidth-percent 20 remaining ratio 100
!
interface Integrated-Cable1/1:3
cable bundle 1
cable rf-bandwidth-percent 20 remaining ratio 100
!

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mbowe
No point reserving too much

As you say, you dont need to reserve much... DBS will automatically share the bandwidth between narrow and wideband interfaces. Basically you can set bandwidth-percent 1 remaining ratio 100 on each interface / channel and everything will work fine.

The only reason to reserve bandwidth is if you applications like packetcable voice. Such flows require "reserved bandwidth" and will not come up unless there is sufficient reserved capacity.

For example if you are running G.711, you probably need to budget around 100Kbps per voice call. If dont reserve enough bandwidth on your integrated-cable interfaces, your first X number of calls will work, but then when you hit X+1, the new calls will fail. So on my system we set integrated-cables to 16 remaining 100. The widebands are 1 remaining 100.

Capm
Thanks mbowe! And I gotta

Thanks mbowe! And I gotta say, your first reply to the multiple wideband interfaces thread, solved a problem for me that I've been having with this Trililithic 860 4x4 meter since we got it 2 years ago... so, Thanks again! :)

mbowe
No worries! I have learnt

No worries! I have learnt heaps from these forums, so always keen to try and give back. :-)

jorge enrique s...
DBS

I want to know if i have this configuration and I put a profile on CM 2.0 it can reach the speed 50 Megas or not?
interface Modular-Cable5/1/0:0
cable bundle 1
cable rf-bandwidth-percent 50 46
!
interface Modular-Cable5/1/0:1
cable bundle 1
cable rf-bandwidth-percent 46
!
interface Modular-Cable5/1/0:2
cable bundle 1
cable rf-bandwidth-percent 46
!
interface Modular-Cable5/1/0:3
cable bundle 1
cable rf-bandwidth-percent 46
!
interface Modular-Cable5/1/0:4
cable bundle 1
cable rf-bandwidth-percent 46
!
interface Modular-Cable5/1/0:5
cable bundle 1
cable rf-bandwidth-percent 46
!
interface Modular-Cable5/1/0:6
cable bundle 1
cable rf-bandwidth-percent 46
!
interface Modular-Cable5/1/0:7
cable bundle 1
cable rf-bandwidth-percent 46
!
interface Wideband-Cable5/1/0:0
cable bundle 1
cable rf-channel 0 bandwidth-percent 50
cable rf-channel 1 bandwidth-percent 50
cable rf-channel 2 bandwidth-percent 50
cable rf-channel 3 bandwidth-percent 50
cable rf-channel 4 bandwidth-percent 50
cable rf-channel 5 bandwidth-percent 50
cable rf-channel 6 bandwidth-percent 50
cable rf-channel 7 bandwidth-percent 50
!

I think that the CM can´t because the modular cable reserved 46 % for the frequency (37 Megas) is that right?

gary mccall
Ideal Dynamic Bandwidth Sharing settings

I have several 7225 uBRs with the settings as below. they lack the "remaining ratio 100"
does the cmts default to 'remaining ratio 100' or should i add it or does it matter?
also the only D2 modems in my systems are some Arris MTAs. Is the "bandwidth-percent 50' too high?
thanks
gary

interface Wideband-Cable1/0:0
cable bundle 1
cable rf-channel 0 bandwidth-percent 50
cable rf-channel 1 bandwidth-percent 50
cable rf-channel 2 bandwidth-percent 50
cable rf-channel 3 bandwidth-percent 50
cable rf-channel controller 1 channel 0 bandwidth-percent 50
cable rf-channel controller 1 channel 1 bandwidth-percent 50
cable rf-channel controller 1 channel 2 bandwidth-percent 50
cable rf-channel controller 1 channel 3 bandwidth-percent 50

mbernardi
what version of IOS do you have?

What version of IOS do you have? The CMTS doesn't add the remaining ratio by default, it needs added manually. I would recommend adding the "remaining ratio 100" to your wideband and narrowband(integrated cable) interfaces. From how I understand it, the commands you have will only allow 50% of the available downstream bandwidth for each channel to either narrowband or wideband modems. So, if you are using DOCSIS(not Euro) @ 256QAM, you get about 38Mbps of useable bandwidth. That means a hard limit of 19Mbps on each channel is available to D2 modems and 19Mbps*8 for your D3 modems. By using the "remaining ratio 100" it allows both D2 and D3 modems to "share" all of the 38Mbps.

It's very confusing at first but one day it will just click. At least it did for me.

gary mccall
thanks so much

That may be why we seem to have some congestion.
again thanks!
gary

gary mccall
Cisco IOS Software, 7200 Software (UBR7200P-JK9SU2-M), Version 1

Cisco IOS Software, 7200 Software (UBR7200P-JK9SU2-M), Version 12.2(33)SCG5, RELEASE SOFTWARE (fc1)

mbernardi
Yes, that could be why you

Yes, that could be why you have congestion issues but not see bandwidth "maxed" out. That version of IOS defiantly supports the "remaining ratio" command. Good luck!

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