1. Emergency Calling Services (Calls for police, fire, ambulance, etc.)
SIPPING WG
IETF 58
Tom Taylor

2. Looking at Emergency Calling Service (Calls to police, fire, ambulance, etc.)
Call Origin
Emergency Call Centre Location
PSTN
IP Network
PSTN
Legacy
EMERGING
draft-schulzrinne-sipping-emergency-req
SIP Phone
draft-schulzrinne-sipping-sos
NOW!
draft-taylor-sipping-emerg-scen

3. Issues Considered Identifying emergency calls
SIP phone or network may have to recognize numbers
universal emergency URI a partial solution
have to distinguish between regular and hearing impaired ECCs in some jurisdictions
Routing from the SIP phone to the target ECC
depends on caller location
Presenting caller location at the ECC
calling party number used to determine caller location
PSTN may determine calling party number based on incoming circuit
Presenting callback number at the ECC
PSTN gateway may have to provide limited-lifetime number, map back to non-numeric SIP URI
Holding the caller accountable for the call
tradeoff: user/device authentication vs. importance of handling emergency

4. Possible Solutions Depend On The Application Scenario
Target
ECC
PSTN
Gateway
Emerg.
Services
abc
def
ghi
jkl
SIP Phone:
stationary
vs.
nomadic
PSTN
Gateway
ECC
SIP
network DB DB DB
Routed as emergency call
Routed as ordinary call

5. Looking Forward Requirement to carry location info in SIP
confidentiality, integrity – applies to call signalling as a whole
usable by proxies, PSTN gateways for call routing
may be inserted by SIP phone or by proxy
ideally, could be constructed by SIP phone based on manual configuration
hotel room example
Potential BCP work for devices
Potential BCP work for network operation