A plurality of public safety answering points (PSAPs) are accessible via a voice-over-packet (VoP) network. Each wireless access point of the VoP network is identified by a basic service set identifier (BSSID). A mobile node associates with a wireless access point and stores the wireless access point's BSSID as an indicator of the mobile node's location. A user of the mobile node dials digits for an emergency services call. In response, the mobile node transmits a SIP INVITE message that includes the BSSID and an additional indicator of the mobile node's location, e.g., determined using GPS or tower triangulation. A SIP proxy server receives the SIP INVITE message and attempts to determine the appropriate PSAP to answer the call based on the BSSID. If the attempt is unsuccessful, the SIP proxy server determines the appropriate PSAP based on the additional indicator.