GST for E Commerce Operator

There are 2 supplies taxable in case of e commerce operator:
1. Service provided by E commerce operator to Vendor (for which commission is charged)

2. Sale of goods by vendor to customer.

In below cases, whether IGST will be levied for both the above supplies? or will CGST/SGST be levied?

Case 1:
Vendor is in state A.
Customer is in State B.
E commerce operator is in State A.


Case 2:
Vendor is in State A.
Customer is in State A.
E commerce operator is in State B.