This value is the third forward traffic descriptor parameter (typically the maximum burst size, when the traffic descriptor type includes an MBS component) associated with this failed call, per the description. This completes the forward traffic contract details alongside Param1 and Param2 for the same failed SVC, and an unusually large burst-size value here relative to the port's buffer provisioning would be consistent with a call admission control rejection due to burst-tolerance limits rather than average-rate limits. This level of detail is mainly useful when the failure cause points at bandwidth/QoS rather than routing or protocol errors.