Re: Question about QoS on C3750

That is actually a really good and tough question. When you are talking
about interface buffers you are essentially just talking about memory that
is allocated to store frames for a particular interface. I have never seen
any numbers from Cisco that actually tell you what those buffers are in
terms of bytes or anything else other than percentages. I guess I was
assuming that 25% of the interface buffers would allow you to buffer 25% of
the line rate, but I'm really not sure. Perhaps somebody can offer some
more specific information on that topic.

On Mon, Jul 18, 2011 at 11:02 PM, kawaii mak <kawaii00mak_at_gmail.com> wrote:

> Dear Joe Astorino,
>
> Thanks. Means the percent of buffer is refer to the interface bandwidth ??
>
> Kawaii
>
> 2011/7/18 Joe Astorino <joeastorino1982_at_gmail.com>
>
>> I think you should be just fine with the default queueing mechanisms if
>> you put your video traffic in the priority queue. The default buffers give
>> you 25% of the interface buffer in the priority queue and 400% maximum
>> (borrowing from the common pool). 25% of your Gig interface gives you
>> 250Mb/s
>>
>> To see what you have allocated check out "show mls qos queue-set" and "sh
>> mls qos interface <x/y> queueing"
>>
>> On Mon, Jul 18, 2011 at 4:10 AM, kawaii mak <kawaii00mak_at_gmail.com>wrote:
>>
>>> Dear Expert,
>>>
>>> I have a question about QoS apply on C3750 egree 1-GE uplink (Trunk)
>>> interface with SRR queueing system. I need to allow the video traffic
>>> (~200M) with high priority to use the GE uplink while the 1G uplink was
>>> congested. How can I do that ?? The following is my question:
>>>
>>> Is it request to mark the cos of cs5 for the Video vlan traffic and set
>>> the
>>> cs5 with queue1 upder assigned queue-set as priority queue1 ??
>>> Is the default queue set enough to priority the 200M streaming traffic go
>>> first while the 1G link was congested ??
>>> How to check the actually buffer bandwidth (e.g. bps) of the allocated
>>> bandwidth for each queue ??
>>> Or how to check the actually allocated bandwidth (e.g. in bps) for each
>>> queue ??
>>> For each queue, default configuration sets 400% as the maximum memory
>>> before
>>> dropped. How to check 400% is equal (in bps)??
>>>
>>> P'se help!!! Thank.
>>>
>>> Regards,
>>> Kawaii
>>>
>>>
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>>
>>
>> --
>> Regards,
>>
>> Joe Astorino
>> CCIE #24347
>> Blog: http://astorinonetworks.com
>>
>> "He not busy being born is busy dying" - Dylan
>>
>>
>

-- 
Regards,
Joe Astorino
CCIE #24347
Blog: http://astorinonetworks.com
"He not busy being born is busy dying" - Dylan
Blogs and organic groups at http://www.ccie.net