Transcript PPT Version

Emergency Calling Services
(Calls for police, fire, ambulance, etc.)
SIPPING WG
IETF 58
Tom Taylor
[email protected]
Looking at Emergency Calling Service
(Calls to police, fire, ambulance, etc.)
Call Origin
PSTN
Emergency Call Centre Location
PSTN
IP Network
Legacy
EMERGING
SIP Phone
NOW!
draftschulzrinnesipping-sos
draft-taylorsipping-emergscen
draftschulzrinnesippingemergency-req
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
Possible Solutions Depend On The Application
Scenario
Target
ECC
PSTN
Gateway
abc
def
ghi
jkl
SIP Phone:
stationary
vs.
nomadic
PSTN
Gateway
Emerg.
Services
ECC
SIP
network
DB
DB
Routed as emergency call
Routed as ordinary call
DB
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