A mobile operator may wish to exclude specific network types from the
total data usage calculated by a device. For example, network traffic
over an MMS APN may be “zero-rated” by a mobile operator. To support
this, the set of network types used to calculate total data usage can
be configured through the config_data_usage_network_types resource
at build time.
Some mobile radio implementations may have unique Linux network
interfaces for each active APN, while other radios may force multiple
APNs to coexist on a single interface. Android can collect network
statistics from both designs, but config_data_usage_network_types is
not be effective at excluding APNs forced to coexist on a single
interface.