Traffic-shape frustration on 2514 router

[fvgelder]

Dear everyone,

I'm having some problems fine tuning the Cisco Traffic-shape command (IOS v.12.0(6)) for my Cisco 2514 router.

In the environment outside the router, I have a mere 10kbps bandwidth at my disposal. I am not, under any circumstance, allowed to exceed that limit. This is my configuration:

traffic-shape group 101 40000 10000 10000 1000

And it is the closest I can come to keeping the bandwidth at around 7 kbps. Using this config line however, also causes the occasional spike, way above the alloted 10kbps.

What I would like to know is how do I use the traffic shape command so that the router allows full use of the alloted 10kbps but never any traffic in excess?

Thanks a bunch for any help you may be able to offer me, I'm baffled.

Felix van Gelder.

 

[plcdoc]

Just to be clear. You are using an access list with this?

Without an access list the config should be:

traffic-shape rate (bit-rate [burst-size excess-burst-size]])

With an access list it should be:

traffic-shape group (access-list bit-rate [burst-size [excess-burst-size]])

Have you applied traffic shaping to both inward and outward interfaces? (i.e., WAN and LAN) You will need to restrict both to stay under 10Kbps total. Traffic-shape affects only outbound on an interface.

 

[fvgelder]

Thanks for the speedy reply.
In answer to your question, yes, I have set up access lists - this is because the 10kbps limit applies to each host on the WAN that our server communicates with. Pardon me for not mentioning that earlier.

My traffic shaping is only setup on the outbound (WAN) interface, because that is where the restriction is imposed. Do you think applying traffic shaping to the inbound interface would help at all in eradicating the occasional peaks that I can see?

As for the syntax you displayed, I'm a bit fuzzy on it's application - and I think that's where I'm making an error.
If I set the TS policy to the following:
traffic-shape group 101 10000 8000 8000
Then the amount of traffic actually allowed to pass through is WAY below 10kb, whereas I would really want traffic shaping to 'max out' the traffic to 10kb before shaping it and delaying packets. No matter what I try, I can't seem to accomplish this.

Thanks again for your help,

Felix.

 

[plcdoc]

Try setting the rate only. No "burst rate" entry:
traffic-shape group 101 64000
Mostly, because you DON"T want to burst above your shaping limit.

Remember, set the access list to cover all types of traffic. Either IP or (TCP,UDP,ICMP,etc.).

And do apply the group statement on all interfaces. Total load on the circuit is inbound+outbound traffic.