H.7 Interworking class
24.0083GPPCore network protocolsMobile radio interface Layer 3 specificationRelease 18Stage 3TS
H.7.1 Cause No. 127 "interworking, unspecified"
This cause indicates that there has been interworking with a network which does not provide causes for actions it takes; thus, the precise cause for a message which is being sent cannot be ascertained.
Annex I (informative):
GPRS specific cause values for GPRS Session Management