Re: Traffic shaping question

Anybody?

On Mon, Jun 4, 2012 at 3:19 AM, Ivan Hrvatska <ivanzghr_at_gmail.com> wrote:
> Hi,
> this TS topic sometimes confuse me so I will ask you, experts, on one task:
>
> "The FR link speed should target a transmission rate of 512 kbps
> although the service provider does allow bursting to port speed (1536
> Mbps). BECNs shouldn't be processed."
>
> OK. Let say we have FR p2p between two routers. So let see if I get this:
> Traffic is always send out of queue at interface speed (clock rate).
> So in this task Tc is not mentioned and it should stay 125 ms? If
> Tc=125ms, that means in each Tc interval serial interface can send max
> 192 kbps for sending at full int speed. To achieve CIR=512 kbps, at
> each Tc interval, interface should send Bc= 64 kbps, which means that
> in takes around 42 msec to send Bc amount of traffic and we have
> around 83 msec in every Tc which can be utilized by excess burst.
> Right?
> Now we come to excess burst. Since the task says "service provider
> does allow bursting to port speed", does that mean that at each Tc
> interval we can send Bc+Be, where Be=AIR/8 - Bc = 128 kbps?
> Theoretically, we can burst non stop to interface speed in this task
> and achieve speed of T1 here? What is correlation between this burst
> in this task and the Be in tasks where there is only average shaping
> put as task? If the task didn't mention "provider allows burst" should
> I still need to configure Be? Not for the purpose of bursting till
> interface speed, just for burst if there was periods of inactivity
> with Bc over interval.
> The term "excess bursting". Is it only used for bursts while there was
> time of inactivity with Bc traffic so that the average speed over 1
> sec at the end should not be more than CIR?
>
> I have two configuration solutions and could you tell me are those
> solution doing same thing:
>
> 1) map-class frame-relay SHAPE
> frame-relay cir 512000
> frame-relay bc 64000
> frame-relay be 128000
> int s1/0.1
> frame-relay interface-dlci 204
> class SHAPE
>
> 2) policy-map SHAPE
> class class-default
> shape average 512000 64000 128000
> int s1/0.1
> service-policy output SHAPE
>
> In solution 1) frame-relay cir ? says:
> R4(config-map-class)#frame-relay cir ?
> <1-45000000> Applied to both Incoming/Outgoing CIR, Bits per second
> in Incoming CIR
> out Outgoing CIR
>
> If shaping is only egress process why command frame-relay cir allows
> IN and OUT direction?
>
> Thanks.

Blogs and organic groups at http://www.ccie.net
Received on Wed Jun 06 2012 - 15:10:54 ART