A calling-station-id can be configured at SAP level and can be included in the RADIUS authentication and accounting messages. This attribute is used in legacy BRAS to identify the user (typically phone number used for RAS connection). In the broadband networks this was replaced by circuit-id in Option 82. However, the Option 82 format is highly dependent on access-node (AN) vendor, which makes interpretation in management servers (such as RADIUS) difficult. Some operators use the calling-station-id attribute as an attribute indicating the way the circuit-id should be interpreted. The calling-station-id attribute can be configured as a string which is be configured on the SAP. It can also be configured to use the sap-id, remote-id, or mac-address.