From: David Duncon (david_ccie@hotmail.com)
Date: Wed Dec 29 2004 - 08:25:33 GMT-3
Ok, now I know where you are coming from , Bob :-) Thanks.
Can I ask you one last Q before we exit this topic ?
I am not 100% on this max-reference bandwidth command's functionality. From
my understanding MQC is by default is only uses 75% of the target CIR of the
circuit. And if you want to use MQC engine to use more than 75% of the
available CIR , then you use this max-reference bandwidth command to tweak
this behavior.
Now let me take help of an example to push my doubts across.
So let us say we have a P2P VC an Access & CIR of 1024k and 256k
respectively. And I have configured " Access of 1024k " on the serial
interface with a "bandwidth command. But at L2 I have , I have adaptive
shaping becn (with mincir of 257000) and throttle down to the real CIR of
256k in the event of congestion.
Now these are my doubts,
1) I was in impression that Frame relay predominantly takes the mincir value
as the primary reference value , so unlike any other WAN protocols , we do
not necessarily need to configure the max-reference bandwidth command on the
serial interfaces. Am I on right school of thought ?
As a mater of fact , that is what I am running on my production network.
While running LLQ & CBWFQ at L3 and A/shaping at L2 , I am not using this
command at all on our frame circuits . And every things works as per specs
or user requirements. So I was wondering when do I need to use this command
on the ground.
2) Secondly as I mentioned above , I normally configure the Access value on
each VC as my bandwidth command under serial int or sub interfaces at both
the ends. So I assume that Queuing engine will look at the Access value of
1024k as the reference point (to take 75% of that ###) at L3 and then
A/Shaping engine will look at MINCIR value of 256k , then how does it work.
Do you see my confusion ?
May be I am thinking too many unnecessary aspects or I am bit confused on
how L2 shaping config interacts with L3's Queuing before the actual 0s and
1s are clocked on to the wire.
I appreciate your guidance on this long running & confused issue :(
Cheers
- David.
>From: "Bob Sinclair" <bsin@cox.net>
>To: "David Duncon" <david_ccie@hotmail.com>,<ccielab@groupstudy.com>
>Subject: Re: Class class-default
>Date: Mon, 27 Dec 2004 22:32:55 -0500
>
>Hi David,
>
>When I reserve bandwidth for a class and apply that policy to an interface,
>I should see the Available Bandwidth parameter decrease from 75% (default
>max-reservable). Each time I reserve more bandwidth in an applied policy I
>should see Available bandwidth (show interface) correspondingly decrease.
>This did not happen when I entered the command to reserve bandwidth for
>class class-default, further suggesting that the command is not effective.
>
>HTH,
>
>Bob Sinclair
>CCIE #10427, CCSI 30427, CISSP
>www.netmasterclass.net
>
>----- Original Message ----- From: "David Duncon" <david_ccie@hotmail.com>
>To: <bsin@cox.net>; <ccielab@groupstudy.com>
>Sent: Monday, December 27, 2004 8:58 PM
>Subject: Re: Class class-default
>
>
>>Appreciate your feedback, Bob.
>>
>>As I did not quite get your point (attached clip bellow) , can you please
>>elaborate ?
>>
>><clip> it does not decrease available bandwidth on the interface. <clip>
>>
>>Cheers
>>
>>- David
>>
>>>From: "Bob Sinclair" <bsin@cox.net>
>>>To: "David Duncon" <david_ccie@hotmail.com>,<ccielab@groupstudy.com>
>>>Subject: Re: Class class-default
>>>Date: Mon, 27 Dec 2004 08:17:17 -0500
>>>
>>>David,
>>>
>>>I would say definitely option 1. Is the bandwidth command really
>>>effective in class class-default? On my box it takes the command, but it
>>>does not show up in the output of "show policy-map interface," and it
>>>does not decrease available bandwidth on the interface.
>>>
>>>HTH,
>>>
>>>Bob Sinclair
>>>CCIE #10427, CCSI 30427, CISSP
>>>www.netmasterclass.net
>>>
>>>----- Original Message ----- From: "David Duncon"
>>><david_ccie@hotmail.com>
>>>To: <ccielab@groupstudy.com>
>>>Sent: Monday, December 27, 2004 2:54 AM
>>>Subject: Class class-default
>>>
>>>
>>>>Hi Group,
>>>>
>>>>I got a Q on MQC 'c class class-default behavior. And appreciate your
>>>>guidance on this.
>>>>
>>>>On production network, let us consider that we have end to end L3 MQC
>>>>policy which primarily aimed to protect Business critical apps such as
>>>>Voice and Citrix and bundled every other traffic type such as File
>>>>transfers , HTTP and Emails ..etc in to a common default class with
>>>>random detect feature enabled. Since there is a bit of concern on the
>>>>email (MS Exchange & Lotus Notes Domino) traffic with in a default class
>>>>as we are seeing some drops there. So If we were to segregate &
>>>>prioritize email traffic from the rest of default class traffic , then
>>>>which of the following options is the better way to go. Either to leave
>>>>the email traffic with in class class-default and assign a guaranteed
>>>>bandwidth or to segregate email traffic in to separate class-map with in
>>>>policy-map. The reason I am asking this Q is to understand any negative
>>>>impacts the NON time sensitive email traffic can bring in to policy maps
>>>>processing where already time sensitive traffic types (Voice & citrix)
>>>>are being serviced.
>>>>
>>>>
>>>>Option 1:
>>>>=================
>>>>
>>>>Policy-map data
>>>>
>>>>Class voice
>>>>Match access-group xxx
>>>>Priority xxx
>>>>
>>>>Class citrix
>>>>Match access-group xxx
>>>>Bandwidth xxx
>>>>
>>>>Class email
>>>>Match access-group xxx
>>>>Bandwidth xxx
>>>>
>>>>Class class-default
>>>>Random detect
>>>>
>>>>Option 2:
>>>>==================
>>>>
>>>>Policy-map data
>>>>
>>>>Class voice
>>>>Match access-group xxx
>>>>Priority xxx
>>>>
>>>>Class citrix
>>>>Match access-group xxx
>>>>Bandwidth xxx
>>>>
>>>>Class class-default
>>>>Random detect
>>>>Bandwidth xxx ---------------------------------------> emails are
>>>>bundled together along with file transfers & HTTP traffic with in class
>>>>default.
>>>>
>>>>
>>>>And my Qs are :
>>>>
>>>>1) is there any way where we can create 2 class-maps with in class
>>>>class-default , one for email and the rest for all default traffic ? If
>>>>yes is there any benefit in doing that ?
>>>>
>>>>2) or is it safe for me to create another class-map for email and slot
>>>>that in with policy-map itself along with voice & citrix and dedicate
>>>>certain amount of bandwidth to it.
>>>>
>>>>3) Thirdly , what is the between a class class-default with a bandwidth
>>>>command and one with out a bandwidth command. And also what is the
>>>>difference between a class class-default with a random detect command
>>>>and one with out it. Though I do aware the functionality of congestion
>>>>avoidance techniques such as WRED and RED , I was in the impression that
>>>>besides configuring random detect , you need to map it to a relevant
>>>>DSCP code which underlines a certain level of drop probability. In other
>>>>words, you are telling the policy engine on what type of traffic you
>>>>want her to drop should she pick up any early congestion warnings.
>>>>
>>>>
>>>>Any feed back is much appreciated.
>>>>
>>>>- David.
>>>>
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>>>>_______________________________________________________________________
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>>>>
>>>
>>>
>>
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>
>
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