Emergency Text Messaging using SIP MESSAGE draft-kim-ecrit-text-00 Jong Yul Kim Wonsang Song Henning Schulzrinne Pietr Boni Michael Armstrong IPR disclosure: https://datatracker.ietf.org/ipr/1253/ IETF 77

Introduction How to use page-mode messaging for emergency? Using SIP MESSAGE for session-less IM and SMS For the endpoints that do not support session-based text (e.g., Real-time text, MSRP) Draft contains: Overview of operation UAC behavior Proxy behavior Conversion to SIP MESSAGE IETF 77

Overview of operation . . . … IM Network SMS Network Resolve ESRP Create soft state for each IM caller Static routing after the first LoST query PSAP SIP Proxy ACD Call Takers Conference Server Emergency Services IP Network (ESInet) Emergency Services Routing Proxy (ESRP) Location-to-Service Translation (LoST) Server IP PSAP A … . . . IP PSAP Z Create soft state for each text caller Static routing after the first LoST query IM Network IM Client SIP Proxy Resolve ESRP LoST Server SMS Network - Create record for each text caller - Static routing after first call taker assignment Cellular phone SMS-SIP Gateway Create soft state for each SMS caller Static routing after the first LoST query IETF 77

UAC behavior Basically, follows rules from both: MESSAGE urn:service:sos SIP/2.0 To: urn:service:sos From: caller@sms.com Route: esrp@ng911.net Geolocation: cid:caller@sms.com; inserted-by=”caller@sms.com” Content-Type: multipart-mixed; boundary=”--- =_RjhENkI3RjQ” ----- =_RjhENkI3RjQ MIME-Version: 1.0 Content-ID: caller@sms.com Content-Type: text/plain Content-Transfer-Encoding: 8bit Hello, I need help. Content-ID: caller@sms.com Content-Type: application/pidf+xml Content-Transfer-Encoding: UTF-8 <PIFO-LO omitted> Basically, follows rules from both: SIP MESSAGE (RFC 3428) Framework for Emergency Calling using Internet Multimedia (draft-ietf-ecrit- framework-10) Also, sends MESSAGE consistently to the same ESRP or the same outbound proxy during conversation. Next hop is fixed after first MESSAGE is sent. IETF 77

Proxy behavior Stores a record to track MESSAGE requests. (Source SIP URI, next hop, expiration timer) Routes all subsequent MESSAGE requests from the same source to the same next hop. Resets expiration timer when receiving subsequent MESSAGE. Deletes record if timer expires. Above only applies to proxies that route MESSSAGE based on policy or location. (e.g. ESRP) From header field of MESSAGE Record valid time in seconds Either ESRP or PSAP URL from first LoST query IETF 77

Conversion to SIP MESSAGE SMS-SIP/IM-SIP gateway converts SMS/IM messages to SIP MESSAGE requests. Type of information Where to place in SIP MESSAGE Origination address or number From header field Destination address or number* (if not urn:service:sos) History-Info header field User message Body Location information Geolocation header field and body * To header and request URI should be urn:service:sos. IETF 77

Related issue: location in SMS (Not part of this draft, but needs to be solved) Location delivery: out of band: there is (generally) no p-ANI also fails for international visitors, among others in-band: add information to SMS 160 limit  compression IETF 77