When responding to a SendAuthInfo.req, we need to differentiate
an error case caused by an unknown IMSI, or an error caused by
an error regarding accessing the database or data integrity.
We also introduce a 'gsup_router' which enables us to route
a transaction to a given VLR. It works based on the SERIAL attribute
communicated at time of the IPA multiplex setup as part of the CCM
sub-protocol.
Harald Welte