This attribute specifies the tolerable cell loss ratio (CLR) for CBR traffic except for connections managed by a Vpt CA. The number is the negative logarithm (base 10) of the CLR. For example, if the target CLR = 1E-10 then Cbr cellLossRatio = 10. This number must be the same as the RtVbr cellLossRatio since CBR and rt-VBR traffic have the same discard priority. The Cbr cellLossRatio is used by the Connection Admission Control (CAC) algorithm to compute the required (equivalent) cell rate for CBR connections.

There is a trade-off between the service category CLR and the achievable link utilization. To guarantee an excellent service category, the CLR should be as small as possible (e.g., 1E-10). However, a smaller CLR results in a larger equivalent cell rate for a given connection and hence a lower link utilization.

Setting this attribute to 0 means that a CLR of 1 can be tolerated. In this case, no bandwidth is reserved for CBR connections, and CAC is effectively turned off. All CBR connections are admitted.