From: Huan Pham (Huan.Pham@peopletelecom.com.au)
Date: Mon Jun 30 2008 - 03:48:24 ART
Hi Narbik,
Thanks for your explaination. May I know what would be the best answer
to this question. Obviously, the first part of it will be answered by
bandwidth 128 command. I am more intrested in how you work out the
parameter for the second part. I mean, should we leave Be, Bc default,
and just configure shape peak with CIR = 256. Many thanks.
"Assign WEB traffic the minimum of 128K, and allow it to peak at 512K"
________________________________
From: Narbik Kocharians [mailto:narbikk@gmail.com]
Sent: Monday, 30 June 2008 3:40 PM
To: Huan Pham
Cc: ccielab@groupstudy.com
Subject: Re: shape peak and shape average confusion
When you need to shape the traffic, there are two types of shaping
available to you:
Average rate shaping: Average rate shaping limits the transmission rate
to the CIR. Using the CIR ensures that the average amount of traffic
being sent conforms to the rate expected by the network.
Peak rate shaping: Peak rate shaping configures the router to send more
traffic than the CIR. To determine the peak rate, the router uses the
following formula:
Peak rate = CIR(1+Be/Bc)
Remember that with Shape Peak, shaping allows the router to burst higher
than average rate shaping. However, the traffic sent above the CIR CAN
be dropped if the network becomes congested.
On Sun, Jun 29, 2008 at 8:31 PM, Huan Pham
<Huan.Pham@peopletelecom.com.au> wrote:
I am not sure about using shape peak command. Appreciate if
someone can
share some clarification.
The most confusing fact is that if you configure "shape peak
512000",
without optional Bc and Be parrameters (i.e. using default), you
are
actually allow traffic to burst to 1024K (double the configured
rate).
R5#
!
policy-map SHAPE
class WEB
shape peak 512000
int s0/0
service-policy output SHAPE
R5# sh policy-map int s0/0
Serial0/0
Service-policy output: SHAPE
Class-map: WEB (match-all)
0 packets, 0 bytes
5 minute offered rate 0 bps, drop rate 0 bps
Match: protocol http
Traffic Shaping
Target/Average Byte Sustain Excess Interval
Increment
Rate Limit bits/int bits/int (ms)
(bytes)
1024000/512000 3200 12800 12800 25
3200
Adapt Queue Packets Bytes Packets Bytes
Shaping
Active Depth Delayed Delayed
Active
- 0 0 0 0 0
no
Class-map: class-default (match-any)
223 packets, 2899 bytes
5 minute offered rate 0 bps, drop rate 0 bps
Match: any
So how will you best answer this question?
Assign WEB traffic the minimum of 128K, and allow it to peak at
512K.
This archive was generated by hypermail 2.1.4 : Tue Jul 01 2008 - 06:23:23 ART