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