From: Ryan Morris (ryan@egate.net)
Date: Wed Oct 31 2007 - 08:25:49 ART
Hi Rudi,
I think two things could be at play here:
First, if you're overloading all the queues you'll get drops no matter
what your QoS policy is, which would cause your TCP flows to back off.
This may be reducing the bandwidth used by your critical apps.
Second, the bandwidth will be dynamically allocated. If your voice calls
are using only 10% of the bandwidth, and your critical traffic 5%, the
algorithm will allow your best effort traffic to take up the rest of the
85% of the available bandwidth. This is by design.
How are you testing the critical data? If you have a traffic generator,
try putting 25% voice, 50% critical and the rest best effort. The extra
voice will be policed, and the rest should be delayed to get the ratio
you've configured. I haven't tried this test yet with my scenario. I
hope to do this kind of test early next week. I'll let you know how it
goes.
Regards,
Ryan Morris
CCIE #18953
On Wed, 31 Oct 2007, Rudi Sutiono wrote:
> Hi everyone,
>
> Now I'm developing QoS for my customer and I have some problems regarding QoS
> that make me confuse, could you guys help me with this problems.
> Current condition: My customer has 2 site offices (Jakarta and Surabaya), the
> interconnection using 10Mbps WAN link, I want to do QoS for the WAN link with
> this breakdown:
> * Voice: 20% priority queue (to cover all the VoIP calls)
> * Critical: 40% use for database application (Oracle), mail
> application (Exchange), and some critical applications
> * Best Effort: Everything else
> With this current breakdown, I want to make sure that voice & critical
> application still get best service when the WAN link congested with other's
> traffic. To test this condition, I make the WAN link congested using WAN
> killer application, all of the 10Mbps bandwidth used by best-effort class (use
> "show policy-map" command). After that, I try to do large database replication
> for Oracle (critical class) hoping that critical class will get 40% of the
> bandwidth. But it takes very long time to map fairly between the classes,
> because after 15 minutes transfer, the critical class only gets 5% of the
> 10Mbps bandwidth (use "show policy-map" command). The questions are:
> 1. Is this the normal QoS behavior or not?
> 2. How long the time QoS takes to map fairly between the classes?
> Because if it takes too long time, will affect the voice and critical class
> performance.
> 3. What is the best QoS implementation for WAN link and MPLS? Can you
> guys give me details of QoS implementation for WAN link and MPLS link (also
> the configuration)?
>
> Any thoughts or real world experience would be appreciated.
>
>
> Best Regards,
>
>
> Rudi Sutiono
>
> _______________________________________________________________________
> Subscription information may be found at:
> http://www.groupstudy.com/list/CCIELab.html
This archive was generated by hypermail 2.1.4 : Fri Nov 16 2007 - 13:11:19 ART