04.083GPPMobile radio interface Layer 3 specificationRelease 1998TS
Cause value = 17 Network failure
This cause is sent to the MS if the MSC cannot service an MS generated request because of PLMN failures, e.g. problems in MAP.
Cause value = 22 Congestion
This cause is sent if the service request cannot be actioned because of congestion (e.g. no channel, facility busy/congested etc.)