Port based rate limiting - Help!

Im going to use a 440 as a "WAN" switch for 2 customers. Im going to have a 20Mbps wan connection terminate on the switch.

Client one gets 18.5Mbps and Client 2 gets 1.5Mbps.

I found this post on the forum;


This is close to what I want I think, but, wont this give them 20Mbps down and 20Mbps up?

I don't want a client to have the potential to consume 40Mbps, cap them at 18.5Mbps in my case.



11 replies

Userlevel 6
Hey Jeremy

This will work for you with some changes. Egress (from switch to customer) is done using the queues. You can assign one customer to QP1 and the other to QP2 then set the max transmit.

For ingress coming into the switch from the customer you need to use a meter. You can create a meter for bandwidth that will stop what the customer can send upstream.

Does this make sense? Do you need us to send the right commands?

So, I would set QP1 to a max transmit of lets say 1.5Mbps and QP2 to 18.5Mbps?

I did the ingress part correctly I think,

create meter Meter-1
configure meter Meter-1 committed-rate 1500 Kbps out-actions drop
create meter Meter-2
configure meter Meter-2 committed-rate 18500 Kbps out-actions drop
configure access-list 1-Ingress ports 1 ingress
configure access-list 2-Ingress ports 2 ingress
Userlevel 6
Hey Jeremy

Yes you can use peak_rate or bandwidth. If you use bandwidth just know it is based on % of port speed

The maximum bandwidth (maxbw) option specifies the peak rate as a
percentage of the maximum port speed. The range is 0 to 100%, and the
default value is 100. When autonegotiation is off, the peak rate is the specified
percentage of the configured port speed. When autonegotiation is on, the
peak rate is the specified percentage of the maximum port speed (the switch
does not detect the negotiated port speed).

You can also set the max per queue per port meaning the settings for a queue can be different on different ports.

Does that help?

Peak_rate seems easier.

If I were to set the peak_rate of qp1 to 1500Kbps, that would then be the maximum egress right?
Userlevel 6
yes give or take a few kbps.

So, question, if I want port 1 to have a total of 1.5 Mbps total; down or up combined, how would I accomplish this? If I set it to 1.5Mbps egress and 1.5Mbps ingress, then they can technically have a max of 3Mbps total, right?
Userlevel 6
well they will only be allowed to pull down or send up 1.5M period so if they try and send a 30Meg file their rate up should be 1.5M If they download a larger video file they will see 1.5M the get to the file will be small but the download will be large. technically they can send 1.5M up and pull down 1.5M.

What is being positioned to the customer normally for cable modem as an example you will be given max speeds 5M upload and 20M download as an example. In my experience if it is not broken out with different speeds then it is understood that ethernet is a bidirectional medium.

So for example if you have a 1G link it is not described as 2G link because you can send and receive at the same time.

My two cents
Makes sense!

How does one deal with bursty traffic then? IE; I want to allow them 1.5U/D usually, but will allow them to burst to 2Mbps. Would I just configure everything to 2Mbps? Is there a CIR and CBIR?
Paul, would you have any documentation on the egress and max transit commands?
Userlevel 6

Sorry for the delay I have been traveling a lot. The best way to look at the commands is using the Command reference guide of of the Extreme website

Here's the command for setting a qosprofile as you can see you can set a committed rate and a peak rate

"configure qosprofile"
"BlackDiamond X8 series switches, BlackDiamond 8800 series switches, E4G-200 and E4G-400"
"switches, SummitStack, and Summit family switches:"

"configure qosprofile egress qosprofile [{minbw minbw_number} {maxbw maxbw_number}"
"| {peak_rate peak_bps [K | M]}] [ports [port_list | all]]"

"configure qosprofile qosprofile [{minbw minbw_number} {maxbw maxbw_number} |"
"{{committed_rate committed_bps [K | M]} {peak_rate peak_bps [K | M]} | [ports"
"[port_list | all]]"

"configure {qosprofile} qosprofile [[{maxbuffer buffer_percentage} {use-strict-"
"priority}] | [maxbuffer buffer_percentage ports [port_list | all]"

Hope that helps
Hello Paul,

I hate to bring up this old thread but I have a similar problem. What I am trying to accomplish is to limit the speed on some ports on Extreme Networks Switch x250 (running firmware version to 5mbps egress and ingress. I am actually more concerned about egress (the speed of the packets leaving the switch and going toward the employee).

I have tried using rate-limit, but that seems to drop packets once the employee exceeds the bandwidth assigned. All ports are connected at 100mbps by default.

What would be the commands that I would have to use to accomplish this?

One of the examples would be the port number 8:

* SW_ITDEPT.29 # show qosprofile ports 8

Port: 8
QP1 MinBw = 0% MaxBw = 100% MaxBuf = 100%
QP8 MinBw = 0% MaxBw = 100% MaxBuf = 100%

I am not sure if the following commands would be appropriate:

configure qosprofile qp1 maxbw 5 ports 8

Thank You!!!