Frame Relay Committed Information Rate (CIR)

Committed Information Rate (CIR) is an important parameter in Frame Relay networks. It is defined as the minimum data rate that is guaranteed to be delivered across a virtual circuit (VC) in a Frame Relay network. CIR is specified by the service provider and is negotiated between the customer and the provider at the time of service activation.

CIR is important because it ensures that a certain amount of bandwidth is reserved for specific traffic flows, which helps to guarantee performance and prevent congestion. At the same time, it also allows for flexible use of the remaining bandwidth on a shared network.

Meaning of CIR

CIR represents the minimum data rate that is guaranteed to be delivered across a virtual circuit. This means that the network will ensure that at least this much bandwidth is available for the traffic flowing on this circuit.

For example, if a network provider specifies a CIR of 64 Kbps for a particular virtual circuit, then the network will ensure that at least 64 Kbps of bandwidth is available for this circuit, even if the network is congested or there are other high-bandwidth flows on the network.

CIR vs. Maximum Data Rate

CIR is often confused with the maximum data rate that can be achieved on a Frame Relay network. The maximum data rate on a network depends on various factors such as the available bandwidth, network congestion, and the number of active flows on the network.

In contrast, CIR is a guaranteed minimum data rate that is reserved for a specific virtual circuit. It is often lower than the maximum data rate on the network, but it ensures that a certain amount of bandwidth is always available for the circuit, even in the presence of congestion.

Conclusion

In conclusion, the Frame Relay Committed Information Rate (CIR) represents the minimum data rate that is guaranteed to be delivered across a virtual circuit in a Frame Relay network. It is an important parameter that ensures performance and prevents congestion. CIR is different from the maximum data rate on the network, which depends on various factors and is not guaranteed.