From: William Chen (kwchen@netvigator.com)
Date: Wed Apr 21 2004 - 13:27:10 GMT-3
Hi Ato,
Thanks. It make sense to me.
I understand that there are two queues when using shaping. DQoS book has
a good explanation to that.
I just wonder, if there is any command available to configure the shaping
queue paramenter of GTS (which I mean the one use the syntax
"traffic-shape").
Best Regards,
William Chen
----- Original Message -----
From: "SANCHEZ-MONGE,ANTONIO (HP-France,ex2)" <antonio.sanchez-monge@hp.com>
To: "'William Chen'" <kwchen@netvigator.com>; <ccielab@groupstudy.com>
Sent: Wednesday, April 21, 2004 4:17 PM
Subject: RE: Traffic Shaping Buffer.
> Hi William,
>
> Shaping takes place BEFORE. The shaping algorithm buffers all the packets
> that exceeded the CIR up to the "shape max-buffers" value. The packets
that
> are within the CIR are scheduled.
>
> If the interface is not congested, the packets are then sent rightaway. If
> it is congested, the fair queue algorithm takes place and the "queue
limit"
> controls how many packets can be buffered by the scheduler.
>
> For example, imagine you want to shape a flow to 64kbps in a T1 interface.
> The T1 interface can have its buffers completely free, so "queue limit"
will
> never kick in. If the real flow for that class is 128kbps, the "shape
> max-buffers" will control the packets queued by the shaping engine.
>
> On the other hand, if you configure "bandwidth 1544" for an interface
whose
> real line rate is 64kbps, you shape a class to 256kbps, and the real
traffic
> flow for that class is 128kbps, the shaping engine will let all go
through,
> but the scheduler will have to drop at least 50% of the incoming packets
as
> soon as "queue limit" kicks in.
>
> Cheers,
> Ato.
>
> -----Original Message-----
> From: William Chen [mailto:kwchen@netvigator.com]
> Sent: miircoles, 21 de abril de 2004 2:47
> To: ccielab@groupstudy.com
> Subject: Traffic Shaping Buffer.
>
>
> Dear all,
>
> I understand that the command "shape max-buffers xxx" is using in a
> CB-Shaping to configure the maximum number of packets will be queued in
the
> shaping buffer. However, what is the difference of the command with
> "queue-limit'? For example:
>
> policy-map testing
> class class-default
> shape average 128000
> shape max-buffers 2048
> fair-queue
> queue-limit 256
>
> R5#sh policy-map testing
> Policy Map testing
> Class class-default
> Traffic Shaping
> Average Rate Traffic Shaping
> CIR 128000 (bps) Max. Buffers Limit 2048 (Packets)
> Weighted Fair Queueing
> Flow based Fair Queueing Max Threshold 256 (packets)
>
> Then, how many packets are allowed to be buffered? 256 or 2048?
>
> Moreover, is there any command to do the similar in GTS?
>
> Best Regards,
> William Chen
>
> _______________________________________________________________________
> Please help support GroupStudy by purchasing your study materials from:
> http://shop.groupstudy.com
>
> Subscription information may be found at:
> http://www.groupstudy.com/list/CCIELab.html
>
> _______________________________________________________________________
> Please help support GroupStudy by purchasing your study materials from:
> http://shop.groupstudy.com
>
> Subscription information may be found at:
> http://www.groupstudy.com/list/CCIELab.html
This archive was generated by hypermail 2.1.4 : Mon May 03 2004 - 19:48:51 GMT-3