ESW April UK Architecture for VoIP 999/112s. John Medland BT 999/112 Policy Manager

Transcription

1 ESW April 2011 UK Architecture for VoIP 999/112s John Medland BT 999/112 Policy Manager

2 UK Emergency Service Public Emergency numbers - 999/112, (ITU v21 text over voice, ie real time text using special terminals) 999/112/ VoIP Networks BT or CW Public Network 31 million calls each year to stage 1 PSAPs, 55% from mobile phones Stage 1 PSAPs BT (5) or C&W (2) Around 60% are connected to Stage 2 PSAPs (usually within 10 seconds) Public network Police 52% Ambulance 42% Fire 6% Fixed/Mobile Networks 999/112/18000 Coastguard <1% (204 Local Controls) (

3 Handling VoIP 112 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 112/ s identified as VoIP Registered default address accessed through E164 tel number (CLI) for fixed users..but default address marked as needing voice confirmation >> Verbal routing Key issues for VoIP 112 : - - only default name+address data from large number of VoIP SPs - challenge of 24 hour VSP contact point for PSAPs (tracing, alternative contact numbers) - lack of information to PSAP for nomadic users Need to Automate Location provision

4 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 and interconnection 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, Huawei, Commscope, Nominet, Magrathea, Aeonvista,Vodafone, VirginMedia, 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) - Cover DSL, Cable, Enterprise, WiFi and GSM scenarios - Use developing standards wherever possible, eg IETF, ETSI - Don t rely on user - Don t rely on device

5 Overview of Architecture and Interfaces VoIP call VSP 2 soft switch (Aggregation + SS7 interconnect ) SBC2 SBC1/2 VSP 1 Soft-Switch SBC1 1 CLI + VSP1 id 2 Source IP+Port, VSP 1 ID and CLI information (NENA v2) a Internet service & access infrastructure providers Access and IP Log-on functions CLI + VSP1 id PSTN IP Gateway PIG 3 LIS URI IAIC b IP VPC 4 c ISP LIS Key Emergency Handling Authority Stage 1 PSAP Request using CLI, VSP id. Response gives location HELD third party request using Source IP (+ Port no.), in HELD ID extensions. Response gives PIDF-LO Voice path Data path

6 Changes required VSP to develop new interface to PSAP ISP to develop LIS and new interface to PSAP, and in some cases to Access Network ISP and Access Network to ensure OSS/CRM systems kept updated and that real time systems (eg Radius Servers) exchange appropriate information 112 PSAP to develop VPC to bring together all information

7 VPC Functions operated by PSAP receiving 112 in UK VSP Soft Switch IAIC (IP Address to ISP Converter) Interface ( b) Parameter (Source Public IP Address) Interface (a) Key Parameters (CLI, Source Public IP Address, source port number) VoIP Positioning Centre Inteface(b) Parameter (ISP LIS URI) Interface ( c ) Parameter (Source Public IP Address) Emergency Handling Agency - Stage 1 PSAP Interface (4) Parameter (CLI) Interface (4) Parameter (Location) Interface( c ) Parameter (PIDF-LO Location) ISP LIS

8 VPC - Mapping Source IP address to ISP IAIC BGP4 Route Collector IP Address IP / AS mapping BGP Route Updates BGP Peers Interface (b) LIS URI AS / LIS mapping

9 Generic LIS Functions operated by ISP (and perhaps also by Broadband Provider) Interface (c) LIS HELD Server ib1 translation; Border Functions - NAPT/SBC/ALG LIS im1 OSS Systems il2 ic1 Other LIS Network elements

10 L2TP Network Server L2TP Access Concentrator DSLAM Residential G/W Voice Terminal Broadband and ADSL Access User Environment Local Loop Provider Backhaul & Aggregation Provider Internet Service Provider Emergency Handling Centre Internet Telephony Service Provider OSS LLP OSS BAP OSS ISP Management Control RADIUS Server (RADIUS) LIS VPC (RADIUS) RADIUS Server (RADIUS) (RADIUS) SIP IP N/W RTP/RTCP Media Figure E1: xdsl Architecture for PPP Tunnelled via L2TP to ISP

11 BB Customer OSS LLP OSS BAP OSS ISP LIS Provision BB Service Req (Billing Adrs, Inst Adrs) BB Service Req (Ref ISP,MPF,Inst Adrs) BB Service Req (Ref BAP, MPF, Inst Adrs) BB Service Resp (Ref BAP, SID LLP ) BB Service Resp (Ref ISP, SID BAP ) LIS Add Info (SID BAP, Inst Adrs) Audit BB Inst Adrs Audit Req (List[SID LLP ]) BB Inst Adrs Audit Resp (List[SID LLP,Inst Adrs]) BB Inst Adrs Audit Req (List[SID BAP ]) BB Inst Adrs Audit Resp (List[SID LLP,Inst Adrs]) LIS Add/Remove/Modify Info (SID BAP, Inst Adrs) Figure E5: BB Provision and Audit on a MPF Line For Binding of Service Identifier (SID) to Installation Address (Inst Adrs)

12 L2TP Network Server L2TP Aggregation Concentrator DSLAM Residential G/W BAP RADIUS Server ISP RADIUS Server LIS PPP Link Est Req PPP Challenge(Token) PPP Link Est Req PPP Challenge(Token) L2TP Tunnel Establishment PPP Resp (UID,#PW#) PPP Response (UID,#PW#, IA=SID BAP ) RADIUS Auth Req (UID,Token,#PW#,IA=SID BAP ) Auth Accept (L2TP Tunnel End Pt, Tunnel Id) L2TP Tunnel Est Req (Tunnel Id,UID,Token,#PW#) RADIUS Auth Req (UID,Token,#PW#,IA=SID BAP ) PPP Link Est Resp PPP Link Est Resp L2TP Tunnel Est Resp Auth Accept PPP IPCP Config Req (IP Adrs) PPP IPCP Config Resp RADIUS Accounting Req (IP Adrs,SID BAP ) NB This example shows the case of an Intermediate Agent at the DSLAM signalling the SID BAP and the ISP s LNS allocating IP Addresses. RADIUS Accounting Resp RADIUS Accounting Req (IP Adrs,SID BAP ) RADIUS Accounting Resp Figure E2: Network Attachment for PPP Tunnelled via L2TP to ISP

13 Way Forward for UK NICC Standard published Jan 2010 technically feasible New requirements on all organisations (systems development) Many more organisations involved to deliver 112 (not just traditional telcos providing physical access networks but VSPs and ISPs) New operational entities : LIS (ISP + Access Ntwk) and VPC (112 PSAP) New interfaces for all organisations : based on international standards as far as possible (eg IETF HELD). Increased co-op and trust relationships between PSAP/VSP, PSAP/ISP and ISP/Access networks Timescales to implement uncertain : technically feasible but money needs to be found NICC Work to continue : other use cases documented

14 Any Questions??