ESRN (Emergency Services Routing Number)

The ESRN is used by the Call Server/Routing Proxy to route an emergency call to the correct ESGW, and by the ESGW to select the desired path to the appropriate SR for the call. In the past, these numbers may have been dialable or non-dialable. As of 2012 these numbers should be non-dialable, and all new ESRKs will be non-NANPA, non-dialable ten-digit numbers.