Bandwidth monitoring is automatically setup - no limits or shaping by default, just monitoring.
You can view user traffic usage with showTraffic in console. File is in path so works anywhere. This displays bandwidth and traffic usage per user for the past week, this includes SFTP, FTP, SCP and Torrent traffic.
This uses kernel level tracking and conntrack module to do it, it monitors all packages sent by certain UID on all protocols. Only outgoing packages are tracked, and only network utilization metrics are being collected.
To view complete server usage vnstat has been installed, ie. vnstat -d will display per day statistics and vnstat -m will display per month statistics.