Emergency Services in PacketCableTM 2.0Emergency Services in PacketCableTM 2.0Sandeep SharmaSenior Architect, Signaling Protocols

SDO Emergency Services Coordination Workshop, Columbia University, New YorkOctober 5 and 6, 2006

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CableLabs IntroductionCableLabs Introduction

• Established in 1988, CableLabs is a non-profit, research and development organization for the cable industry Members are exclusively cable system operators Board of Directors is made up of member company CEOs Technical leadership is provided by member company CTOs

• There are currently 52 member cable companies representing 82 million cable subscribers in North America, Latin America, Europe, and Japan US (62M) Canada (7M) Europe (10M) Japan (1.5M) Latin America (1.5M)

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CableLabs’ MissionCableLabs’ Mission

• Plan, fund and perform R&D projects CableLabs works with the manufacturing community to

develop technology to meet the business and strategic initiatives of its members

• Funnel relevant research to member companies Serve as a clearinghouse to provide information on

current and prospective technological advances through strategic and technical assessments

Develop technology for new businesses• Foster equipment development

Interoperability specifications and certification activities• Coordination with relevant industry fora

ITU, 3GPP, ETSI, SCTE, IETF, UPnP, DLNA

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What is PacketCableTM?What is PacketCableTM?

• The PacketCableTM project was founded in 1997 to develop an architecture for real-time IP communication services over cable PacketCable 1.0 and 1.5

– An end-to-end architecture for providing IP-based digital telephony services

– Signaling based on MGCP to the endpoints and SIP between call management servers, provisioning, QoS, management, PSTN interconnect, accounting, security, codecs

– Leveraging DOCSIS® 1.1 and 2.0 access network technologies PacketCable Multimedia

– A QoS architecture that support a wide range of QoS-enabled, beyond-voice services

– Leverages existing mechanisms defined in PacketCable 1.0&1.5 and DOCSIS 1.1 & 2.0

PacketCable 2.0– Defines an end-to-end architecture for providing real-time IP

communication services based entirely on SIP and 3GPP IMS– Extend cable’s existing Internet Protocol service environment to accelerate

the convergence of voice, video, data, and mobility technologies

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IMS in PacketCable 2.0IMS in PacketCable 2.0

P-CSCF

I-CSCF

ApplicationServers

HSS

Subscriber Management

Applications

Session Control

Handsets

SLFS-CSCF

GPRS/other GSM

PSTN Interconnect via PacketCable 1.5

Policy Control via PacketCabl

e Multimedia

IP connectivity via DOCSIS

Access Network

PacketCable 2.0 integrated an IMS core into the cable architecture

Interconnect with PacketCable 1.5 digital telephony

networks and clients (E-MTAs)

Cable clients

Client-managed NAT & Firewall

Traversal

Cable-based provisioning, management,

and accounting

Enhancements based upon cable requirements

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Application Agnostic ArchitectureApplication Agnostic Architecture

ResidentialSIP Telephony

Wireless &Cellular

Integration

VideoApplication

XYZApplication

Cable Application Servers

Telephony ClientWiFi/Cellular

ClientVideo Client

PacketCable 2.0 Network

(IMS based)

P-CSCFS-CSCFI-CSCF

BGCFOSS

HSS

Cable Clients

Soft Client

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PacketCable 2.0 Residential SIP Telephony (RST)PacketCable 2.0 Residential SIP Telephony (RST)

• Application that makes use of PacketCable 2.0 architecture• 5 published documents:

http://www.packetcable.com/specifications/packetcableapps.html• Provides traditional North American residential digital telephony

features• Examples of supported features:

Caller ID / Calling name delivery Call Forwarding (multiple variants) Call Blocking (inbound, outbound) Multi party features (Call Waiting, Hold, Transfer, Three Way calling) Call History (Auto recall, Auto callback) Operator Services Emergency Services Do Not Disturb, Distinctive Alerting, Message Waiting, Speed Dialing,

Call Trace• Rest of the presentation references PacketCable 2.0 RST Feature

Specification

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RST Emergency Services ScopeRST Emergency Services Scope

• Identification and storage of location information by UE

• Identification of emergency calls at UE and/or CSCF servers

• Conveyance of UE location information in SIP signaling for emergency calls

• Special handling (establishing QoS and priority treatment) for emergency calls – post I01

• Handling of emergency calls at SIP Proxies and PacketCable 2.0 routing server functions

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RST Emergency Services AssumptionsRST Emergency Services Assumptions

• Applicability of NENA i1, i2 and i3• Use of IETF protocols and methodologies for location

determination and conveyance• Location information is provided to UE via DHCPv6/v4• UE supports DHCP protocol and associated options for

geographical location (RFC 3825) and civic location (draft-ietf-geopriv-dhcp-civil-09)

• UE supports SIP multipart MIME (RFC 3261) and SIPPING location conveyance I-D with PIDF-LO object(s) to convey location information in SIP message bodies

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RST Emergency Call HandlingRST Emergency Call Handling

• At UE boot time UE request its location from the access network using DHCP UE is provisioned by its home network backoffice systems with

the digit map that identifies the emergency dial string• When an emergency call is initiated, UE sends an INVITE with

the universal emergency service URN “URN:service:sos” as Request-URI and To: header

• INVITE request also includes the location obtained from DHCP in its message body in the form of PIDF-LO as defined in draft-ietf-sip-location-conveyance-04

• The P-CSCF detects the emergency call and forwards the call to E-CSCF

• E-CSCF follows the procedures outlined in RST specification for the various NENA phases to forward the call to PSAP

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RST Emergency Services UE RequirementsRST Emergency Services UE Requirements

• Minimum UE state (registered and authenticated)• Emergency calling configuration (e.g. digit map)• Obtain location using DHCP• Recognition of an emergency call• Basic call modifications while on an emergency call• PSAP Operator Ringback• PSAP Callback (PSAP originated emergency call)• Feature Interactions• Signaling Identification of an emergency call

Priority: emergency• Media QOS for emergency call

Mark media packets with special DSCP values

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RST Emergency Services P-CSCF RequirementsRST Emergency Services P-CSCF Requirements

• Recognition of UE-originated emergency call• Forwarding the call to an E-CSCF• Handling of Network-initiated de-registration

during emergency calls

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RST Emergency Services E-CSCF requirementsRST Emergency Services E-CSCF requirements

• Call routing in NENA i3 architecture Use location in INVITE to determine Request URI of PSAP (using draft-ietf-

ecrit-lost-01 for example), currently left FFS as IETF documents mature Forward INVITE to PSAP URI

• Call routing in NENA i2 Use location in INVITE to determine ESRN and ESQK (from a VoIP

Positioning Center VPC) Route INVITE to ESGW (on to PSAP)

• Call routing in NENA Pre-i2 E-CSCF routes to dedicated selective router Selective router routes to PSAP based on telephone number of caller Location in INVITE not used

• Call routing in NENA i1 Call is routed to telephone number associated with PSAP Does not make use of dedicated selective router Route INVITE to MGC Call treated as normal PSTN call

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ReferencesReferences

• CableLabs http://www.cablelabs.com

• DOCSIS® Specifications http://www.cablemodem.com/specifications/

• Overall PacketCableTM project http://www.packetcable.com

• PacketCable 2.0 project http://www.packetcable.com/specifications/specifications2

0.html• Residential SIP Telephony

http://www.packetcable.com/specifications/packetcableapps.html

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Thank YouThank You

• Feedback is welcome• CableLabs specifications are intended to be

revised as IETF and other standard requirements mature

• For further information, email to s dot sharma at cablelabs dot com

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Backup slide 1 (Emergency call)Backup slide 1 (Emergency call)Interconnect and PSTNPhone

“A”UE“A”

PacketCable Network

PSAP

Two-way communications

Answer

INVITEPriority:emergency

Alerting

200 OK

200 OK

Off-hook

ACK

ACK

Dial Tone

911

INVITEPriority:emergency

183 with SDP

183 with SDP

PRACK

PRACK

200 OK PRACK

200 OK PRACK

Ringback Tone