NAS to NAS Replication

Hi all, I just bought a QNAP TS-251 and originally I have a Buffalo LinkStation LS-CHL-V2. I would like to enable NAS to NAS Replication from the QNAP to LinkStation but it said "rsync" is needed to enable. Any Ching know does LinkStation has "rsync" function? If not, any other way to perform NAS to NAS Replication?

Thank you so much!!!!