This value records the broadband bearer traffic type for this failed call, per the description, chosen from notIndicated(1), cbr(2) for constant bit rate, or vbr(3) for variable bit rate. Since CBR and VBR traffic are typically admitted against different bandwidth reservation rules on an ATM switch, this field tells an admin which admission-control path this specific call was evaluated under, which matters when correlating a bandwidth-related failure cause with the right provisioning parameters. Failures concentrated on vbr(3) calls, for instance, would point at variable-rate traffic-shaping limits rather than fixed CBR reservation exhaustion.