This value records the broadband bearer class requested for this failed call, per the description, chosen from class-A(1), class-C(3), or class-X(16) as defined for B-ISDN bearer capability. This is a coarse-grained service-type classifier (roughly, constant-bit-rate/circuit-style traffic versus variable/connection-oriented data traffic) that, alongside the traffic descriptor fields, helps identify what kind of application was behind this specific failed call. A cluster of failures concentrated in one bearer class would point at a service-type-specific provisioning gap on this port rather than a generic capacity problem.