Bandwidth fine tuning

[NDP]

Hello,

Good day. 

Thanks everyone for the wonderful support ....  we are trying to fine tune the bandwidth configurations on our Circuits and need your help 

we have .policing  enabled for Netbios trafficon our LAN metro circuit  and 30 % of bandwidth is allocated ( with bandwidth command), rest all traffic is allocated 70 % bandwidth. This is causing slowness when multiple users are copying data .  we never see that circuit is 100 % utilized. 

Could someone please let me know if we can tune the QoS configuration in such away that Netbios can occupy the excess bandwidth available and it should not cause any bandwidth starvation for rest all traffic cause that is critical. 

if there is congestion, the non-netbios traffic should not be dropped . 

I think priority queueing can be enabled but not expert on Queuing technology :-( need your help

Thanks in advance

[Joseph W. Doherty]

What platform, IOS version, IOS feature set?

[NDP]

Hi Joseph,

version is 12.2 (33) SXJ

VSS switch between 6509 E chassis

Sup- 720

police cir has been configured for weekday's  ( time based ACEs ) Netbios traffic

please let me know if any more information is required . Thanks in advance

[Joseph W. Doherty]

What's your MetroE bandwidth (both physical, and CIR [if one])?

[NDP]

physical 400 Mbps

CIR for policing is 40000000 bc 1250000

single token bucket

[Joseph W. Doherty]

Disclaimer

The Author of this posting offers the information contained within this posting without consideration and with the reader's understanding that there's no implied or expressed suitability or fitness for any purpose. Information provided is for informational purposes only and should not be construed as rendering professional advice of any kind. Usage of this posting's information is solely at reader's own risk.

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Posting

Thanks for the additional info.

Basically, 6500s using their typical LAN line cards offer poor advanced QoS support, the kind you need to meet your shaping requirements.

What would likely work best is a router's QoS, but for 400 Mbps you're looking at a high end 3900 or a low end 4400.

What might be an improvement, would be an "inexpensive" 2960, in-line, as I believe they can "shape" a port, and then you can prioritize across 4 egress queues, when there's congestion.  Any queue can use otherwise unused bandwidth.

Unsure it would be much better, for you, than a 2960, but a MetroE switch, also in-line, might offer some additional QoS features.

I'm unsure the 6500 offers anything better.  The older FlexWAN cards were QoS rich, but I don't believe they support 400 Mbps.  There are other "WAN" line cards, but I believe they are restricted to the 7600 series.

PS:

Oh, I also recall, VSS setups further limit line card support.

[NDP]

Thanks Joseph...

i don't think there is a plan for another device . 

what if we mark Non-bios traffic which is production traffic as priority-level 1 under one class-map and netbios traffic as priority-level 2 in another class-map

in congestion, doest it help us to forward only production traffic ?

not sure if 6500 chassis supports this .. 

Thanks

[Joseph W. Doherty · Accepted solution]

Disclaimer

The Author of this posting offers the information contained within this posting without consideration and with the reader's understanding that there's no implied or expressed suitability or fitness for any purpose. Information provided is for informational purposes only and should not be construed as rendering professional advice of any kind. Usage of this posting's information is solely at reader's own risk.

Liability Disclaimer

In no event shall Author be liable for any damages whatsoever (including, without limitation, damages for loss of use, data or profit) arising out of the use or inability to use the posting's information even if Author has been advised of the possibility of such damage.

Posting

The problem with 6500 LAN QoS, it can prioritize different traffic, but prioritization is when there's congestion, which only happens when the port is congested.  When you have subrate bandwidth, you'll have a downstream congestion issues, but your switch won't deal with it.

Policing doesn't create congestion.  You can insure some traffic cannot use over its allocated bandwidth, but the precludes using all available bandwidth, and it's not the same.

Basically, the 6500, with LAN cards, does not lend itself to a subrate bandwidth hand-off.  If you want to effectively deal with your problem, you need something "better".

[NDP]

Thanks Joseph..