Setting The Committed Burst Rate; Setting The Excessive Burst Rate - HP 7102dl - ProCurve Secure Router Configuration Manual

Setting Up Quality of Service
Configuring Rate Limiting for Frame Relay
You shape Frame Relay traffic by setting the committed burst value (B and
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the excessive burst value (B ).These values determine how much bandwidth
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the Frame Relay subinterface can use when the line is and is not congested.
The total burst values for all PVCs on an interface should be less than the
interface's access rate to save bandwidth for overhead bits the router does not
count when calculating transmission rates. If you set the burst rates too high,
the connection will become oversubscribed and queues will build. The access
rate is the physical rate limit; manually limiting traffic to this rate is unneces-
sary and defeats the purpose of traffic shaping.

Setting the Committed Burst Rate

Your service level agreement (SLA) with your Frame Relay provider specifies
the bandwidth that the provider guarantees each PVC, or the PVC's committed
information rate (CIR). The CIR is calculated from the B , which is the
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maximum number of bits that the service provider guarantees to forward
during a certain interval of time (T). The CIR is B /T.
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You should set a B for each Frame Relay subinterface to ensure that the PVC
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does not exceed its CIR. Some service providers penalize you for consistently
transmitting more than the agreed-upon amount of traffic.
You configure the value in bits. Because the Secure Router OS, like most
service providers, always considers the time interval to be one second, the B
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is effectively the CIR. To set the B , enter the following command from a Frame
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Relay subinterface configuration mode context:
Syntax: frame-relay bc <bits>
You can set a B between 0 and 4,294,967,294 bps. For example, if your SLA
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guarantees a CIR of 1 Mbps, enter:
ProCurve(config-fr 1.101)# frame-relay bc 1000000

Setting the Excessive Burst Rate

The B sets the maximum number of bits that the router can transmit during
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T. The B determines the rate at which the router can burst data above the
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committed rate when the Frame Relay network is not congested.
On the ProCurve Secure Router, the B is the number of bits beyond the B
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that the router can transmit, so the upper limit for bandwidth available on the
interface is the sum of the B and B .
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