ITU-T / ATIS Workshop
“Next Generation Technology and Standardization”
Las Vegas, 19-20 March 2006
Emergency Services and
Priority Signaling
Martin Dolly
AT&T
(With credit to Percy Tarapore (AT&T) for Priority contributions)
ITU-T
What are Emergency Services?
o Government Emergency Services
• Emergency Telecommunications Service (ETS) –
ETS extends the functional requirements, capabilities and
applications of Governments Emergency Telecommunications
Service/Wireless Priority Service (Gets/WPS), including multimedia
services for National Security and Emergency Preparedness (NS/EP)
communications over multiple network environments, including endto-end IP-based packet networks.
• Telecommunications for Disaster Relief (TDR) –
TDR is an application of (or the use of) an international
telecommunications capability on a per occasion basis for purposes
of disaster relief and mitigation. Network and service facilities
used to support TDR may or may not be dedicated to the TDR
application alone.
o Civil Emergency Services (e.g., E911 in USA)
ITU-T
ITU-T / ATIS Workshop “Next Generation Technology and
Standardization“
Las Vegas, 19-20 March 2006
2
Emergency Telecommunications Service (ETS)
o Requires priority treatment in the IP network
infrastructure to support of National Security /
Emergency Preparedness (NS/EP) communications.
o Has capabilities to increase the probability of
successful completion of calls, sessions, or other
communications, initiated by government authorized
users over the public network infrastructure.
o Also includes legacy circuit-switched NS/EP services
such as Government Emergency Telecommunications
Service (GETS) and Wireless Priority Service (WPS).
(TIA uses the term “Wireless Priority Service” whereas 3GPP uses the term “Priority Service”)
ITU-T
ITU-T / ATIS Workshop “Next Generation Technology and
Standardization“
Las Vegas, 19-20 March 2006
3
IP-ETS Phase 1 - ATIS Standards
o IP-ETS Phase 1
• ETS within and between IP based service provider
networks.
• Currently in the approval process.
• Architectural Agnostic
• Phase 1 addresses:
— Procedures for interoperability/interworking between IP-based
and existing circuit-switched wireline and wireless service
provider networks;
— Basic (“GETS-like”) authentication mechanisms and procedures;
— Security requirements.
o Packet Priority Marking Release 1:
• In Letter Ballot Process
ITU-T
ITU-T / ATIS Workshop “Next Generation Technology and
Standardization“
Las Vegas, 19-20 March 2006
4
IP-ETS Phase 2 - ATIS Standards
o IP-ETS Phase 2:
• Issue statement (project statement of work)
was approved, and will create a Standard that
defines protocol and procedures for supporting
ETS in NGN/IMS, with a focus on security and
authentication on IP access.
• Work Directed to ITU SG 11 for signaling.
• Authentication and Security:
—Work Directed to Recommendations in ITU-T SG13
—To be Aligned with a Standards in ATIS
ITU-T
ITU-T / ATIS Workshop “Next Generation Technology and
Standardization“
Las Vegas, 19-20 March 2006
5
IP-to-IP Network Interconnection, IP Access Network
Technology Boundary
Core 2
Originating Access Core 1
A
A
ETS-DNRPH=ets.DF
RPH=ets.DFx
RPH=ets.x
CPC=NS/EP
A
B
ETS-DN
RPH=ets.DF
RPH=ets.DFx
C
RPH=ets.x CPC=NS/EP
Um
Default priority
value
Used on Um
interface
A
ETS-DN
D
Terminating Access
RPH=ets.DF
RPH=ets.x
RPH=ets.x
RPH=ets.x
A
WPS-FC+DN
Um
ITU-T
RPH=ets.DFx
RPH=ets.y, wps.y
RPH=ets.y, wps.y
RPH=ets.y, wps.y
ITU-T / ATIS Workshop “Next Generation Technology and
Standardization“
Las Vegas, 19-20 March 2006
RPH=ets.y, wps.y
6
Network Element Capability needs
o Setting SIP RPH (P-CSCF/A-BGF, MGCF/MGW)
o Passing and Acting on SIP RPH (all elements)
o SIP-SS7 Interworking, TDM HPC, Trunk Queuing, TDM HPC
o
o
o
o
o
o
o
Measurements (MGCF/MGW/SGW)
H.248 Priority for NS/EP if Applicable
Processing Priority (all elements)
Priority Access at Resource Admission (Applicable PDP & PEP
elements)
Exemption from NM and Congestion Controls (all Applicable
Elements)
Vertical Interface (setting DCSP) Support to Trigger Layer 3
Priority (layer 2 also if needed, all elements)
RPH, NMx measurements (all applicable elements)
Access to the NS/EP AS, MS (for authentication) – with applicable
interfaces
ITU-T
ITU-T / ATIS Workshop “Next Generation Technology and
Standardization“
Las Vegas, 19-20 March 2006
7
ATIS Functional Architecture and Interfaces
Rr/Ro
IMS Core functions
Sh
SIP
H.248
DIAMETER
Other
SCIM
MRB
HSS
AS
Charging Function
Dh
ISC
Cx
Mw
S-CSCF
SLF
Mw
Cx
Rf/Ro
Dx
IWF
I-CSCF
Mi
Ib
Mi
Mr
Mg
Mw/Mk/Mm
P-CSCF
P-
Gm
MGCF
SGF
SGW
MSMp
PSTN
GW
Access
SBC
A-BGF
MRFP
PSTN/ISDN
PSTN
If
MRFC
Id
Interconnect
SBC
T-MGF
MGW
ITU-T
Ic
SEG
Mj
UE
IBCF
ITU-T / ATIS Workshop “Next Generation Technology and
Standardization“
Las Vegas, 19-20 March 2006
I-BGF
8
Other IP Networks
Mw
BGCF
Ia
ETS Call Flow
SBC
UE
P-CSCF
INVITE ( R-URI, RPH[ets.??)
S/I-CSCF
MS
AS
Toward
Dest.
INVITE ( R-URI, RPH[ets.DF])
INVITE (VXML R-URI, RPH[ets.DF])
INVITE (VXML R-URI, RPH[ets.DF])
NOTE: Ack’s are not shown
200OK [INVITE] (RPH[ets.DF])
200OK [INVITE] (RPH[ets.DF])
200OK [INVITE] (RPH[ets.DF]) 200OK [INVITE] (RPH[ets.DF])
200OK [INVITE] (RPH[ets.DF])
RTP Media
AS Authenticates the User PIN
and Destination Number
http (VXML)
MS responds to AS
with Users Input
BYE (RPH[ets.x])
RTP Media on Hold to User, and
Released from the Media Server
reINVITE (Null-SDP, RRH[ets.x])
reINVITE (SDP, RRH[ets.x])
reINVITE (Null-SDP, RRH[ets.x])
200OK (RPH[ets.x])
reINVITE (Null-SDP, RRH[ets.x])
INVITE ( R-URI=Destination#, RPH[ets.x])
reINVITE (Dest-SDP, RRH[ets.x])
NOTE: remaining set-up messages toward destination are not shown
RTP Media
ITU-T
MS plays tones and
announcements to the
calling user to collect
PIN and Dest.
Number
ITU-T / ATIS Workshop “Next Generation Technology and
Standardization“
Las Vegas, 19-20 March 2006
9
Priority Classification & Signaling ATIS
Committee Efforts
o Priority Classification in IP Networks:
• 3 CAC/Resource Reservation Levels:
— High Priority Reserved for Emergency Traffic (e.g., ETS & E911)
— Technical Report to be Published
• Up to 3 Restoration Levels
— Emergency Traffic to be included in High Priority Traffic
— Technical Report to be Published
o Priority Signaling Issues:
• Technical Requirement in Progress for Separate EF PHB for VoIP ETS
• Requirements Document for Vertical Signaling Interface:
— Traffic Priority & QoS Signaling from Application to User/Media Planes
— Minimum attributes Necessary for Layer 3 Processes (e.g., DiffServ, DS-TE)
— Comprehensive List of Priority and QoS Parameters
ITU-T
ITU-T / ATIS Workshop “Next Generation Technology and
Standardization“
Las Vegas, 19-20 March 2006
10
Thank You
ITU-T
ITU-T / ATIS Workshop “Next Generation Technology and
Standardization“
Las Vegas, 19-20 March 2006
11