Configuration, tuning and performance of policing on Catalyst 6506 switches TCP traffic http://www.cnaf.infn.it/~ferrari/tfngn/cat6500/police/tcp/
is a good document to read and has some nice visual representations ie "Figure 1: relationship between normal burst size and end-to-end TCP performance" "Figure 2: minimum normal burst size needed to achieve a target CIR throughput" "Figure 3: throughput gain introduced with PIR" "Figure 3b: comparison of TCP and UDP performance as a function of the PIR" "Figure 4: relationship between maximum burst size and throughput" --matt > -----Original Message----- > From: [EMAIL PROTECTED] [mailto:cisco-nsp- > [EMAIL PROTECTED] On Behalf Of mack > Sent: Wednesday, November 14, 2007 7:15 PM > To: [email protected] > Cc: [EMAIL PROTECTED] > Subject: Re: [c-nsp] Rate limit on 3750 > > For a single distant host and a 100 mbit line the this seems about right. > Any packet loss on a high latency link really kills speed. > Changing the burst size will help but needs to be tuned to the link. > Lower latency will yield higher values as will smoother traffic or more > hosts. > > Linux has traffic shaping which may be preferable to policing at the > switch. > A linux box will probably do a better job for low traffic values and cost > considerably less than an equivalent switch. A router-on-a-stick > configuration > with a Linux box and sending 'interesting' traffic to it via PBR for > processing > can be used for a lot more than just rate limiting. > > LR Mack McBride > Network Administrator > Alpha Red, Inc. > > > > > Message: 8 > > Date: Tue, 13 Nov 2007 19:45:50 -0700 > > From: Clinton Work <[EMAIL PROTECTED]> > > Subject: Re: [c-nsp] Rate limit on 3750 > > To: William <[EMAIL PROTECTED]> > > Cc: "\[c-nsp\]" <[email protected]> > > Message-ID: <[EMAIL PROTECTED]> > > Content-Type: text/plain; charset=ISO-8859-1; format=flowed > > > > > > Sounds about right for a single TCP session (iperf) and a 30Mbps > > policer. Have you seen the following article from Cisco with discusses > > the differences between shaping and policing? Personally, I really > > dislike using policing on TCP traffic for sub-native speeds because it > > results in a lot of drops as the clients send bursty traffic. I would > > prefer to implement shaping, but very few Cisco boxes support that on a > > budget. > > > > Comparing Traffic Policing and Traffic Shaping for Bandwidth Limiting: > > http://www.cisco.com/warp/public/105/policevsshape.html > > > > William wrote: > > > We have workstation x.x.x.x on port 23, sending data to another host > > > on a distant network. Using iperf to send tcp traffic (defaults) we > > > get a rate of approx 12mb/s. I want to have a max of 15mb/s for > > > 'interesting' traffic. Can anyone tell me where I'm going wrong? > > > > > > The software I'm running is ip services 12.2(25)SEB4 on a 3750. > > > > > > > > -- > > ======================================================= > > Clinton Work > > Airdrie, AB > > > > > > > > > > Message: 11 > > Date: Wed, 14 Nov 2007 10:47:50 +0200 > > From: Tassos Chatzithomaoglou <[EMAIL PROTECTED]> > > Subject: Re: [c-nsp] Rate limit on 3750 > > To: William <[EMAIL PROTECTED]> > > Cc: "\[c-nsp\]" <[email protected]> > > Message-ID: <[EMAIL PROTECTED]> > > Content-Type: text/plain; charset=ISO-8859-7; format=flowed > > > > Maybe try increasing the burst size of the policer. > > > > Also make sure you get this low speed because of drops, otherwise you > > need to increase the tcp > > window and/or number of connections on the iperf hosts. > > > > -- > > Tassos > > > > > > William wrote on 13/11/2007 7:51 ??: > > > Hi, > > > > > > I'm trying to rate limit traffic using class-maps. > > > > > > I believe I've got the config right to police the traffic, however, > > > I'm not getting the rates I want. > > > > > > config goes like: > > > > > > ip routing > > > mls qos > > > ! > > > class-map match-all interesting > > > match access-group 1 > > > ! > > > policy-map interesting > > > class interesting > > > police 32000000 320000 exceed-action drop > > > ! > > > access-list 1 permit x.x.x.x > > > > > > int fa1/0/23 > > > service-policy input interesting > > > > > > > > > We have workstation x.x.x.x on port 23, sending data to another host > > > on a distant network. Using iperf to send tcp traffic (defaults) we > > > get a rate of approx 12mb/s. I want to have a max of 15mb/s for > > > 'interesting' traffic. Can anyone tell me where I'm going wrong? > > > > > > The software I'm running is ip services 12.2(25)SEB4 on a 3750. > > > > > > Cheers, > > > > > > W > > > _______________________________________________ > > > cisco-nsp mailing list [email protected] > > > https://puck.nether.net/mailman/listinfo/cisco-nsp > > > archive at http://puck.nether.net/pipermail/cisco-nsp/ > > > > > > > > _______________________________________________ > cisco-nsp mailing list [email protected] > https://puck.nether.net/mailman/listinfo/cisco-nsp > archive at http://puck.nether.net/pipermail/cisco-nsp/ _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
