From: Petr Lapukhov (petr@internetworkexpert.com)
Date: Thu Jun 29 2006 - 13:21:57 ART
Correct, Chris.
But AFAIK that rule does not work with "shape peak".
It always send up Bc+Be every Tc, effectively ending
with CIR*(1+Bc/Be) rate.
-- Petr Lapukhov, CCIE #16379 petr@internetworkexpert.comInternetwork Expert, Inc. http://www.InternetworkExpert.com Toll Free: 877-224-8987 Outside US: 775-826-4344
2006/6/29, Chris Lewis <chrlewiscsco@gmail.com>: > > Just a note of caution here. The shaper can only utilize the Be tokens if > credit has been built up, meaning that the shaper has been transmitting at > below CIR for a period of time. Be does not allow you to constantly > transmit > at a rate above CIR, it is only available if traffic has dropped below > CIR. > Over time, you should still acerage out at CIR. > > Chris > > > On 6/29/06, Elias Chari <elias.chari@gmail.com> wrote: > > > > Andy, > > > > It is when you configure shape peak 96000 (not average) that you get > upto > > 192k. > > > > If not specified bc and be default to the same value, then peak = 2*CIR > as > > per the formula. Also if only cir and bc are specified the bc value is > > used > > for be > > > > Rack1R1#sh policy-map int s0/1 > > Serial0/1 > > > > Service-policy output: testB > > > > Class-map: testB (match-all) > > 0 packets, 0 bytes > > 5 minute offered rate 0 bps, drop rate 0 bps > > Match: any > > Queueing > > Output Queue: Conversation 265 > > Bandwidth 84 (kbps) Max Threshold 64 (packets) > > (pkts matched/bytes matched) 0/0 > > (depth/total drops/no-buffer drops) 0/0/0 > > Traffic Shaping > > Target/Average Byte Sustain > Excess Interval Increment > > Rate Limit bits/int bits/int (ms) (bytes) > > *192000/96000 1992 7968 7968 83 1992* > > > > Adapt Queue Packets Bytes Packets Bytes Shaping > > Active Depth Delayed Delayed Active > > - 0 0 0 0 0 no > > > > Class-map: class-default (match-any) > > 0 packets, 0 bytes > > 5 minute offered rate 0 bps, drop rate 0 bps > > Match: any > > On 6/29/06, Anderson Mota Alves <mota_anderson@hotmail.com> wrote: > > > > > > Hi Petr, > > > > > > Based on your explanation below it's more clear to me that you cannot > > mix > > > "priority" and "shape" because one is for policing and the other for > > > shaping purposes. > > > > > > But I've been seaching in cisco webpage and from the link below it > says: > > > > > > You can specify two types of traffic shaping; average rate shaping and > > > peak 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 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) > > > > > > > > > http://www.cisco.com/en/US/products/sw/iosswrel/ps1835/products_command_reference_chapter09186a0080087f34.html#wp1077189 > > > > > > > > > But how do I know that configuring the "shape average 96000" I can > send > > > traffic up to 192 kbps? > > > > > > Thanks, > > > > > > Andy > > > > > > -------------------------------------------------------------------- > > > > > > From: "Petr Lapukhov" <petr@internetworkexpert.com> > > > To: "Anderson Mota Alves" <mota_anderson@hotmail.com >, > > > <ccielab@groupstudy.com> > > > Subject: Re: Doubt in QoS > > > Date: Thu, 29 Jun 2006 14:42:55 +0400 > > > >The first one seems to be "almost" correct: > > > > > > > >You shape (limit) traffic up to 96kbit here - the only problem > > > >is "peak" keyword. This configuration actually permits you to send > > > >traffic up to 192kbit by default. So I would better do something > > > >like: > > > > > > > >... > > > >class CRITICAL > > > > shape average 96000 > > > > bandwidth 84 > > > >... > > > > > > > >This way you guarantee 84k in case of congestion, > > > >and limit flow up to 96k in any case. > > > > > > > >As for your second example - you can not mix priority and bandwidth: > > > > > > > >R6(config-pmap-c)#priority 64 > > > >R6(config-pmap-c)#bandwidth 92 > > > >Must remove priority configuration from this class first. > > > > > > > >Also remember that you cannot mix "priority" and "shape", > > > >and dont forget that "priority" actually police your traffic in > > > >case of congestion. > > > > > > > >Finally, you may choose "police" instead of "shape", with > > > >your first example. The decision should depend on task wording. > > > > > > > >HTH > > > >--- > > > >Petr Lapukhov, CCIE #16379 > > > >petr@internetworkexpert.com > > > > > > > >Internetwork Expert, Inc. > > > >http://www.InternetworkExpert.com <http://www.internetworkexpert.com/ > > > > > >Toll Free: 877-224-8987 > > > >Outside US: 775-826-4344 > > > > > > > >----- Original Message ----- From: "Anderson Mota Alves" > > > ><mota_anderson@hotmail.com> > > > >To: <ccielab@groupstudy.com> > > > >Sent: Thursday, June 29, 2006 2:16 PM > > > >Subject: Doubt in QoS > > > > > > > > > > > >>Hi gurus, The question I need to complish is the following: > > > >> > > > >>Which configuration provides the mission-critical traffic class > > > >>with a > > > >>minimum > > > >> > > > >>bandwidth guarantee of 84 kbps and a maximum upper bandwidth limit > > > >>of 96 > > > >> > > > >>kbps? > > > >> > > > >>I think I have to solution for this one but I'm not sure if I'm > > > >>right: > > > >> > > > >>policy-map shape > > > >>class mission-critical > > > >>bandwidth 84 > > > >>shape peak 96000 > > > >> > > > >>or > > > >> > > > >>policy-map shape > > > >>class mission-critical > > > >>priority 64 > > > >>bandwidth 96 > > > >> > > > >>Could anyone tell me which one I could use? Also I don't know if in > > > >>order > > > >>to use the shape peak I need to first configure the shape cir ir > > > >>order to > > > >>make sure that this will be the peak above the Cir. > > > >> > > > >>Thanks > > > >> > > > > > > >>_______________________________________________________________________ > > > >>Subscription information may be found at: > > > >>http://www.groupstudy.com/list/CCIELab.html > > > > > > > _______________________________________________________________________ > > > Subscription information may be found at: > > > http://www.groupstudy.com/list/CCIELab.html > > > > _______________________________________________________________________ > > Subscription information may be found at: > > http://www.groupstudy.com/list/CCIELab.html > > _______________________________________________________________________ > Subscription information may be found at: > http://www.groupstudy.com/list/CCIELab.html
This archive was generated by hypermail 2.1.4 : Sat Jul 01 2006 - 07:57:34 ART