Find my answers
1. Once the Subscriber info has been sent to the visited n/w, in what other scenarios (barring another LU) is the home HLR contacted by the visted MSC/VLR?
> There are some messages (Supplementary Services) for which the VLR may initiate a contact with the HLR.
> The other thing for which i am not very sure is USSD sessions.
2. Is there some way of preventing the billing info to reach the home service provider and instead route it to a 3rd party.
> Billing info is always sent through TAP. So the home operator is not invoved till the TAP records reach it. I did not really understand your question here?
3. Does the visited HLR know, at any point of time, that a international roamer is in the network, or does the home HLR is the one point contact for any subscription info that the visited MSC/VLR may need? Incase there is any info in visited HLR, what is it & how is it updated?
>The visited HLR is not aware of the roamers profile at any point in time.