Emergency Services WorkshopUK “i2” for VoIP 999/112s
John Medland – BT 999/112 Policy Manager
UK Emergency Service today
BT or CW Public TDM Ntwk (PSTN)
Other TDM Networks
BT or CW Operator Centres
PSTN
Police 56%
Ambulance
35%
Fire 8%
Coastguard<1%
999/112/ 18000
999/112/18000
(222 Local Controls)
BT – 28m calls, 55% mobile, every call voice + location
Stage 1 PSAPs
Stage 2 PSAPs
Handling VoIP 999 now• PSAPs still TDM based so VoIP goes through PSTN / IP
Gateways• Small number of VoIP 999s at present, mostly fixed users• Regulation says if PSTN access, then must allow 999 • 999s identified as VoIP• Registered “default” address accessed through E164 tel
number (CLI) for “fixed” users….• ….but default address marked as needing confirmationVerbal routing• Device/CPE use PSTN/GSM for 999 if possible
• Key issues for VoIP 999 : -- only default name+address data from large number of VoIP SPs- challenge of 24 hour VSP contact point for PSAP use (tracing, alternative contact numbers)- lack of information to PSAP for nomadic users
• Need to Automate Location provision………
NICC Task Group• The Network Interoperabilty Consultative Committee : NICC is a
UK telecommunications industry committee which acts as an industry consensus group in which specifications and technical issues associated with network competition can be discussed. It also is a source of technical advice to the UK Regulator
• Location Task Group : Routing 999/112 for VoIP to correct local EA supplying caller location information on all calls
• Membership : BT, C&W, Ericssons, ALu, Huawei, Andrew, ETSI, Magrathea, Thus, IN UK, Virgin Media, Orange, and Ofcom +….
• Approach :-
- VSP, ISP and Access Provider(s) all different organisations- PSAPs are still TDM based- Start with UK only (all parties UK-based) - Start with DSL, then tackle Cable, WiFI and GSM scenarios
- Use developing standards wherever possible, eg IETF, ETSI- Don’t rely on user- Don’t rely on device
Key
VPC
VoIP call
CLI + VSP1 id
VSP 1Soft-Switch
Emergency Handling Authority –Stage 1 PSAP
Internet service & access infrastructure providers
PIGPIG
CLI + VSP1 id
IAIC
Request using CLI, VSP id.Response gives location
1
c
3
4
b
ISP LIS
SBC2
PSTN—IP Gateway
VSP 2 soft switch (Aggregation + SS7 interconnect )
a
SBC1
SBC1/2
Source IP+Port, VSP 1 ID and CLI information (NENA v2)
Access and IP Log-on functions
2
Voice path
Data path
Overview of Architecture and Interfaces
HELD third party request using Source IP (+ Port no.), in HELD ID extensions. Response gives PIDF-LO
LIS URI IP
Broadband and ADSL Access
IP N/W
Voice
Term
ina
l
Management
Control
Media
Resid
ential
G/W
RADIUSServer
RADIUSServer
LIS VPC
OSSISPOSSBAPOSSLLP
(RADIUS)
(RADIUS)
(RADIUS)
L2T
P A
ccessC
oncen
trator
L2T
P N
etwork
Server
(RADIUS)
DS
LA
M
SIP
RTP/RTCP
Figure E1: xDSL Architecture for PPP Tunnelled via L2TP to ISP
UserEnvironment
Local LoopProvider
Backhaul &Aggregation
Provider
Internet ServiceProvider
EmergencyHandlingCentre
InternetTelephony
ServiceProvider
Resid
ential
G/W LIS
DS
LA
M
L2T
PA
ggregationC
oncen
trator
ISPRADIUSServer
Figure E2: Network Attachment for PPP Tunnelled via L2TP to ISP
L2T
PN
etwork
Server
BAPRADIUSServer
L2TP Tunnel Establishment
PPP Resp (UID,#PW#)
RADIUS Auth Req(UID,Token,#PW#,IA=SIDBAP)
PPP Challenge(Token)PPP Challenge(Token)
PPP Response(UID,#PW#, IA=SIDBAP)
RADIUS Auth Req(UID,Token,#PW#,IA=SIDBAP)
Auth Accept
RADIUS Accounting Req
(IP Adrs,SIDBAP)
PPP Link Est ReqPPP Link Est Req
PPP Link Est RespPPP Link Est Resp
PPP IPCP Config Req (IP Adrs)
PPP IPCP Config Resp
RADIUS Accounting Req(IP Adrs,SIDBAP)
RADIUS Accounting Resp
Auth Accept(L2TP Tunnel End Pt, Tunnel Id)
L2TP Tunnel Est Req(Tunnel Id,UID,Token,#PW#)
L2TP Tunnel Est Resp
RADIUS Accounting RespNB This example shows the case of an Intermediate Agent at the DSLAM signalling the SIDBAP and the ISP’s LNS allocating IP Addresses.
BB Service Req (Billing Adrs, Inst Adrs)
BB Service Req (RefISP,MPF,Inst Adrs)
BB Service Req (RefBAP, MPF, Inst Adrs)
BB Service Resp (RefBAP,SIDLLP)
LIS Add Info (SIDBAP, Inst Adrs)
BB Inst Adrs Audit Req(List[SIDBAP])
BB Inst Adrs Audit Req(List[SIDLLP])
BB Inst Adrs Audit Resp(List[SIDLLP,Inst Adrs])
BB Inst Adrs Audit Resp(List[SIDLLP,Inst Adrs])
LIS Add/Remove/Modify Info(SIDBAP, Inst Adrs)
OSSISPOSSBAPOSSLLP LISBBCustomer
Figure E5: BB Provision and Audit on a MPF Line For Binding of Service Identifier (SID) to Installation Address (Inst Adrs)
BB Service Resp (RefISP,SIDBAP)
Audit
Provision
LIS
HELD Server
IP@ translation; Border Functions - NAPT/SBC/ALG
OSS/CRM
Systems
Network
elements
Interface (c)
iL2
iM1
iC1
iB1LIS
Other LIS
Basic UK LIS interfaces
Implications
Yes, automated routing and location provision is technically feasible (for DSL case) but will imply :-
• New requirements on all organisations (systems development)
• Many more organisations involved to deliver 999 (not just traditional telcos but VSPs and ISPs)
• New operational components : LIS and VPC • New interfaces for all organisations: based on
international standards as far as possible (eg IETF HELD)
• Increased co-op and trust relationships between PSAP and VSP, ISP and Access networks
• Detailed document is now in final stage of NICC review process …………………..
Challenges to adoption
• ISPs storing and updating association of IP/Line ID/ location at an ISP LIS
• LIS cascades to access providers and length of response times
• Challenging business cases (!) unless regulatory driven
• Current regulatory responsibility unclear when several CPs and an ISP involved
Next Steps
- Continued work on other UK scenarios (Wireless, Private networks)- International Scenarios : national solns need to evolve to cover international IP roamers- Long transition periods with hybrid TDM/IP services - IP end-to-end (as NGN, PSAP +device capabilities become clear) i3 / IETF Ecrit
Back-ups
Voice
Term
inal
Management
Control
Media
User Local Loop Backhaul & Internet Service Emergency InternetEnvironment Provider Aggregation Provider Handling Telephony Provider Centre Service Provider
Resid
ential
G/W
BAPRADIUS
ServerLIS VPC
OSSISPOSSBAPOSSLLP
iM1 iM2
iM3
SIP
RTP/RTCP
xDSL Architecture for PPP BRAS Terminated Access
DS
LA
M
BR
AS IP N/W
iBB1(PPPoATM)
iBB2(PPPoE)
iBB3(RADIUS)
iBB5(RADIUS)
iBB4(RADIUS)
ISPRADIUS
Server
iM4
Resid
ential
G/W
BAPRADIUS
Server
LIS
DS
LA
M
BR
AS
ISPRADIUS
Server
iBB1(PPPoATM)
iBB2(PPPoE)
iBB3(RADIUS)
iBB5(RADIUS)
iBB4(RADIUS)
PPP Resp (UID,#PW#)
Access Req
(UID,Token,#PW#,IA=SIDBAP)
PPP Challenge(Token)PPP Challenge(Token)
PPP Response
(UID,#PW#, IA=SIDBAP)
Access Acpt
(BRAS Info)
Acc Req
(UID,Token,#PW#,IA=SIDBAP)
Acc Acpt
(IP Adrs)Accouting Req
(IP Adrs,SIDBAP)PPP Success
PPP Success
Accouting Resp
Network Attachment for PPP Terminated Access
HomeHub BB Platform
LocationInfo Svr
IP Adrs-> Line Id
ISP OSS
Line ID -> Installation Adrs
PublicInternet
ITSPCall Svr
IPGate-way
IPeXchange
TDMGate-way
PSTN
EmergencyHandling
CentreVPC
CLI, ITSP -> IP Adrs
CLI, ITSP
CLI+ITSPIP Adrs
Installation Adrs
Installation Adrs
EACR/PSAPEISEC
Installation Adrs
CLI
CLI
Installation Adrs
NICC Standard – end to end