The ISP (Internet Service Provider) or Carrier information can be captured as part of requests but ISP (Carrier) monitoring in EUM in on-premise installations is turned off by default. The ISP feature is behind a feature flag that you will need to explicitly enable.
Set this following property in eum.properties under EUM_HOME/eum-processor/bin directory.
Next, restart the EUM server.
./bin/eum.sh start &