From: Radioactive Frog (pbhatkoti@gmail.com)
Date: Tue Mar 10 2009 - 11:38:50 ARST
I think this has already discussed on here and Pavel Bykhov already smashed
it.
http://www.boxoid.org/cisco/MAX-RESERVED-BANDWIDTH-AND-CBWFQ.pdf
On Tue, Mar 10, 2009 at 7:18 PM, Godswill Oletu <oletu@inbox.lv> wrote:
> Did you have a closer look at the 'show policy-map interface' output?
>> It clearly shows "bandwidth percent 70" resulting in a 70,000kbps
>> bandwidth allocation to the class.
>>
>
> You will get an output similar to what you stated above, if you change the
> maximum reserved bandwith from the default of 75% to 100%
>
> see some example
> !
> policy-map test
> class test1
> bandwidth percent 70
> class test2
> bandwidth percent 30
> !
> interface FastEthernet0/0
> max-reserved-bandwidth 100
> service-policy output test
> !
> !
> BR1#sh policy-map interface fa0/0
> FastEthernet0/0
>
> Service-policy output: test
>
> Class-map: test1 (match-all)
> 0 packets, 0 bytes
> 5 minute offered rate 0 bps, drop rate 0 bps
> Match: protocol imap
> Queueing
> Output Queue: Conversation 265
> Bandwidth 70 (%)
> Bandwidth 70000 (kbps)Max Threshold 64 (packets)
> (pkts matched/bytes matched) 0/0
> (depth/total drops/no-buffer drops) 0/0/0
>
> Class-map: test2 (match-all)
> 0 packets, 0 bytes
> 5 minute offered rate 0 bps, drop rate 0 bps
> Match: protocol snmp
> Queueing
> Output Queue: Conversation 266
> Bandwidth 30 (%)
> Bandwidth 30000 (kbps)Max Threshold 64 (packets)
> (pkts matched/bytes matched) 0/0
> (depth/total drops/no-buffer drops) 0/0/0
>
> Class-map: class-default (match-any)
> 0 packets, 0 bytes
> 5 minute offered rate 0 bps, drop rate 0 bps
> Match: any
> BR1#
>
> <changing the reserved bandwidth back to its default of 75%>
> !
> interface FastEthernet0/0
> service-policy output test
> !
> BR1#sh policy-map interface fa0/0
> FastEthernet0/0
>
> Service-policy output: test
>
> Class-map: test1 (match-all)
> 0 packets, 0 bytes
> 5 minute offered rate 0 bps, drop rate 0 bps
> Match: protocol imap
> Queueing
> Output Queue: Conversation 265
> Bandwidth 70 (%)
> Bandwidth 52500 (kbps)Max Threshold 64 (packets)
> (pkts matched/bytes matched) 0/0
> (depth/total drops/no-buffer drops) 0/0/0
>
> Class-map: test2 (match-all)
> 0 packets, 0 bytes
> 5 minute offered rate 0 bps, drop rate 0 bps
> Match: protocol snmp
> Queueing
> Output Queue: Conversation 266
> Bandwidth 30 (%)
> Bandwidth 22500 (kbps)Max Threshold 64 (packets)
> (pkts matched/bytes matched) 0/0
> (depth/total drops/no-buffer drops) 0/0/0
>
> Class-map: class-default (match-any)
> 0 packets, 0 bytes
> 5 minute offered rate 0 bps, drop rate 0 bps
> Match: any
>
> !
> In both cases my 100% allocation to the policy-map yield different real
> bandwidth to the policy-maps, depending on the max reserved bandwidth
> configured on the interface.
>
>
>
>
>
> Godswill Oletu
> CCIE #16464 (R&S)
>
>
> ----- Original Message ----- From: "Dale Shaw" <dale.shaw@gmail.com>
> To: "Godswill Oletu" <oletu@inbox.lv>
> Cc: "karim jamali" <karim.jamali@gmail.com>; "Cisco certification" <
> ccielab@groupstudy.com>
> Sent: Tuesday, March 10, 2009 4:01 AM
> Subject: Re: max-reserved-bandwidth
>
>
> Hi,
>>
>> On Tue, Mar 10, 2009 at 6:48 PM, Godswill Oletu <oletu@inbox.lv> wrote:
>>
>>> Though you have allocated 95% in your policy statements; you are actually
>>> only using 95% of 75% of the interface bandwidth (or around 71.24% of
>>> 100%
>>> of the interface bandwidth).
>>> <assuming max reseved bandwidth is left at its default of 75%>
>>>
>>
>> Hmmm..
>>
>> If you reduce or increase the max reserved bandwitdth under the
>>> interface;
>>> the real bandwith allocated to each of your class maps will be
>>> recalculated
>>> and change accordingly.
>>>
>>
>> Did you have a closer look at the 'show policy-map interface' output?
>> It clearly shows "bandwidth percent 70" resulting in a 70,000kbps
>> bandwidth allocation to the class.
>>
>> So, the answer to your question is no.
>>>
>>
>> I think the key may be found in the IOS the original poster is running.
>>
>> From:
>> http://www.cisco.com/en/US/prod/collateral/iosswrel/ps6537/ps6558/white_paper_c11-481499.html
>>
>> "max-reserved-bandwidth Command
>> The max-reserved-bandwidth command no longer affects the amount of
>> bandwidth available to a service policy. Any policy-map can allocate
>> up to 100% of the bandwidth without the need of the
>> max-reserved-bandwidth command. The max-reserved-bandwidth command was
>> used in previous IOS releases in order to overcome the restriction of
>> allocating 75% of the bandwidth to user-defined classes. In HQF, that
>> restriction does not exist anymore."
>>
>> And, for reference, here's Pavel Bykov's research from the archives:
>> http://www.boxoid.org/cisco/MAX-RESERVED-BANDWIDTH-AND-CBWFQ.pdf
>>
>> cheers,
>> Dale
>>
>
>
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