Bandwidth consumed when running RMAN backup to shared drive

Hello everyone, 

I have a customer who's running RAC and performing backup to a shared drive from another server.

This is a 3 node RAC and the way the backup was configured is like this:

run{

allocate channel c1 device type disk connect sys/password@rac1;

allocate channel c2 device type disk connect sys/password@rac2;

allocate channel c3 device type disk connect sys/password@rac3;

backup as compressed backupset database format '\\networked\path\db_backup\db%u.bck' filesperset 10;

sql 'alter system switch logfile';

sql 'alter system switch logfile';

sql 'alter system switch logfile';

backup as compressed backupset archivelog all format '\\networked\path\db_backup\arc%u.bck' filesperset 20;