Backup Exec, tape backup file, compression not working

Hi All,

I'm a new user of Symantec BE and find my tape backup job does not compress my data when job is done.

In the options, I choose COMPRESSION: Hardware (If available, otherwise software). but seems not working. 15GB data backup to tape, the used space is 15GB, no compression at all.

Is there any settings related to this function that I need to change?

Thank you.

Jack,