UA recognition & proxy resolution(proxy location determination) 9-1-1 mapping INVITE urn:service:sos To: urn:service:sos Accept-Contact: *;sip.service="urn:service:sos" INVITE sip:psap@leonianj.gov To: urn:service:sos Location: Accept-Contact: *;sip.service="urn:service:sos" provider.com |