Dynamic MS-PWs use single-sided signaling procedures with double-sided configuration; a fully qualified FEC must be configured at both endpoints. That is, one T-PE (the source T-PE: ST-PE) of the MS-PW initiates signaling for the MS-PW, while the other end (the terminating T-PE: TT-PE) passively waits for the label mapping message from the far-end. The TT-PE only responds with a label mapping message to set up the opposite direction of the MS-PW when it receives the label mapping from the ST-PE. By default, the 7210 SAS will determine which T-PE is the ST-PE (the active T-PE) and which is the TT-PE (the passive T-PE) automatically, based on comparing the SAII with the TAII as unsigned integers. The T-PE with SAII>TAII assumes the active role. However, it is possible to override this behavior using the signaling {master | auto} command in the spoke-sdp-fec context. If master is selected at a specific T-PE, it will assume the active role. If a T-PE is at the endpoint of a spoke-SDP that is bound to an VLL SAP, and single-sided autoconfiguration is used, that endpoint is always passive. Therefore, signaling master should only be used when it is known that the far end will assume a passive behavior.