[cisco-voip] [OSL | CCIE_Voice] DSCP to COS map question

[Jonathan Charles]

Well, the upside is I am not taking the test with the crappy 3550s and
6500s... I am taking it with new code 3750s.


Jonathan

On Mon, May 11, 2009 at 7:36 PM, Jorge L. Rodriguez Aguila
<jorge.rodriguez at netxar.com> wrote:
> This is a new OS image. I am glad that Cisco finally decided to switch. The IOS on the lab boxes however have the older 26 code based on the IOS on the lab blueprint and talking from late last year experience.
>
> Jorge
>
> ----- Original Message -----
> From: Jonathan Charles <jonvoip at gmail.com>
> To: Jorge L. Rodriguez Aguila
> Cc: Wes Sisk <wsisk at cisco.com>; ccie_voice at onlinestudylist.com <ccie_voice at onlinestudylist.com>; cisco-voip at puck.nether.net <cisco-voip at puck.nether.net>; Michael Ciarfello <MCiarfello at iplogic.com>
> Sent: Mon May 11 18:47:50 2009
> Subject: Re: [cisco-voip] [OSL | CCIE_Voice] DSCP to COS map question
>
> I just did it on a 3750 running 12.2(50)SE
>
> and I got
>
> mls qos map cos-dscp 0 8 16 24 32 46 48 56
>
> Which throws CS3 into CoS 3
>
>
> Jonathan
>
>
> On Mon, May 11, 2009 at 5:28 PM, Jorge L. Rodriguez Aguila
> <jorge.rodriguez at netxar.com> wrote:
>> It's the other way around.  Auto Qos Defaults are set for AF31 so the qos-dscp map default is 26. To this day I don't understand why the Cisco Switch codes still default to af31 on the Auto QoS settings
>>
>> Jorge
>>
>> -----Original Message-----
>> From: Jonathan Charles [mailto:jonvoip at gmail.com]
>> Sent: Monday, May 11, 2009 5:22 PM
>> To: Jorge L. Rodriguez Aguila
>> Cc: Wes Sisk; ccie_voice at onlinestudylist.com; cisco-voip at puck.nether.net; Michael Ciarfello
>> Subject: Re: [cisco-voip] [OSL | CCIE_Voice] DSCP to COS map question
>>
>> Which was my original question, we used to need to change it because
>> it set it for CS3 and Cisco wanted AF31, now we can leave it alone...
>>
>>
>> J
>>
>> On Mon, May 11, 2009 at 10:29 AM, Jorge L. Rodriguez Aguila
>> <jorge.rodriguez at netxar.com> wrote:
>>> If the exam does not say set for AF31 you have to set it to 24 to match CS3 which is the current Siganlling DSCP used accorting to the SRST (Remember the CCIE Lab is based on this document in most respects)
>>>
>>> Jorge
>>>
>>> -----Original Message-----
>>> From: cisco-voip-bounces at puck.nether.net [mailto:cisco-voip-bounces at puck.nether.net] On Behalf Of Jonathan Charles
>>> Sent: Sunday, May 10, 2009 2:15 PM
>>> To: Wes Sisk
>>> Cc: ccie_voice at onlinestudylist.com; cisco-voip at puck.nether.net; Michael Ciarfello
>>> Subject: Re: [cisco-voip] [OSL | CCIE_Voice] DSCP to COS map question
>>>
>>> Well, my question is do we need to modify it... we used to...
>>>
>>>
>>> J
>>>
>>> On Sun, May 10, 2009 at 8:24 AM, Wes Sisk <wsisk at cisco.com> wrote:
>>>> Is it caused by change in recommended DSCP values over time.  ~4 years ago
>>>> we changed recommended values for signaling at least.
>>>>
>>>> /Wes
>>>>
>>>> On Sunday, May 10, 2009 2:53:26 AM, Jonathan Charles <jonvoip at gmail.com>
>>>> wrote:
>>>>
>>>> Apologies for the lack of clarification...
>>>>
>>>> The switch is a 3750-24PS
>>>>
>>>> The lab is v3.
>>>>
>>>> And yes, I know to trust CoS on trunks and DSCP on access ports to
>>>> servers...
>>>>
>>>>
>>>>
>>>> Jonathan
>>>>
>>>> On Sat, May 9, 2009 at 9:37 PM, Michael Ciarfello
>>>> <MCiarfello at iplogic.com> wrote:
>>>>
>>>>
>>>> I'm a little confused what you are asking exactly.  And I think you have the
>>>> mappings backwards from what your premise statement is.
>>>>
>>>> Depending on switch  / router model or software the COS to DSCP map may
>>>> configure 24 or 26.  If the requirement is to put signaling traffic in CS3,
>>>> then use 24.  Maybe the requirement would be to put it in AF31 so use 26.
>>>>
>>>> Also study up on trust cos vs trust dscp and where to use each and on what
>>>> piece of equipment, etc.  Some 6500 line cards have all sorts of
>>>> restrctions.  QoS SRND has a great discussion of these.
>>>>
>>>> If you have a home lab a sniffer is a great tool to check out the markings
>>>> at various places and make sure they are carrying through.
>>>>
>>>> ah crap, power is flickering, gotta go.
>>>>
>>>> ________________________________________
>>>> From: ccie_voice-bounces at onlinestudylist.com
>>>> [ccie_voice-bounces at onlinestudylist.com] On Behalf Of Jonathan Charles
>>>> [jonvoip at gmail.com]
>>>> Sent: Saturday, May 09, 2009 5:43 PM
>>>> To: cisco-voip at puck.nether.net; ccie_voice at onlinestudylist.com
>>>> Subject: [OSL | CCIE_Voice] DSCP to COS map question
>>>>
>>>> So, autoQoS adds this:
>>>>
>>>> mls qos map cos-dscp 0 8 16 24 32 46 48 56
>>>>
>>>> Yet we are advised to do this:
>>>>
>>>> mls qos map cos-dscp 0 8 16 26 34 46 48 56
>>>>
>>>> Remapping AF31 to COS 3
>>>>
>>>> Well the default puts CS3 into COS 3, which is what you want to do now...
>>>>
>>>> Am I right?
>>>>
>>>>
>>>> Jonathan
>>>>
>>>>
>>>>
>>>> _______________________________________________
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>>>> cisco-voip at puck.nether.net
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>>>>
>>>>
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>>
>