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Video Relay Service and Assignment of Numbersfor IP Based Services

February 16, 2008

Penn Pfautzppfautz@att.com

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Introduction

All proposals seek to provide functional equivalence in reachability and access to emergency services to meet FCC mandates by

– Assigning geographic NANP numbers to relay users– Implementing a central database to support routing by any relay

provider to any relay user– Providing E911 by leveraging the technology deployed for VoIP

• Where they differ is on– Whether users should get numbers thru relay providers or some

new neutral third party– The implementation of the database

• NPAC vs. DNS, • what it contains besides telephone number• who updates it• who can access it

– Whether or not to use a common E911 VPC

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Number Administration

AT&T Favors the “VoIP Model”:

Relay users get numbers from their chosen relay provider

Relay providers get numbers through commercial agreements with voice service providers

Proven model in use today by VoIP service providers

Avoids expense and delay of setting of third party administrator

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Database Implementation

AT&T (like CSDVRS) favors DNS approach:

Standard Internet approach to phone number to IP mapping

Proven technology widely available from many vendors

Contains IP address to support direct connection of any provider with any user (NPAC involves designated provider on all calls, even where the hearing user had selected a different provider)

Unlike CSDVRS

DNS updated by user’s chosen relay provider to accommodate existing user equipment (100K+)

DNS accessed by relay providers– To maintain security– To accommodate existing user equipment

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VRS Provider A

IP

IP Change Updates

Number

IP Change Updates

Hearing to Deaf Call:1.Hearing person can direct dial deaf persons personal telephone number (10 digit NANP #).2.Call routed by LEC to VRS provider.3.VRS provider looks up IPin local or central database and completes VRS call to Deaf user.

Direct Dialed (Hearing to Deaf) Call

SecureDDNS

LEC/ CLEC

IP

Number

Central DB

IP

Number

Local DB

IP

Number

Local DB

VRS Provider B

12 3

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Direct Dialing (Deaf to Deaf)

Deaf to Deaf Call:

1. Deaf user dials 10 digit number of friend (not knowing or caring what device they use).

2. VP queries provider database, VRS provider db queries central db if needed to return current IP address of friend.

3. Direct call established to friend using current IP address.

VRS Provider

IP

SecureDDNS

IP

Number

Central DB

IP

Number

Local DB Number

1

2

3IP

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VRS Provider 1

VRS Provider 2

URI

IP

DNS

NPAC

Dynamic DNS

Number Portability Administration Center

URI

Number

COPY

IP

URI

IP

URI

URI

Number

NPAC

URI Change Updates

VRS Provider

DDNS

IP

IP

Number

IP

Number

3rd Party NPAC

Alternate RelayProvider Selection

Toll Free Number

Toll Free Number

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Deaf 911 Call Flow – Leveraging Current Wireless & VoIP 911 Solutions

911 Location Server

Phone, Name & Street Address

Central db

VRS Provider 1

Phone Number

User dials 911 through any

VRS ProviderVoice

IP Address

911 Routing

Sign Language Routes to proper

911 Call Center

Pre-Emergency Setup:

User registers Phone, Name, & Street Address for 911 purposes

911 Call Center receives caller’s Phone, Name &

Street Address

• When a VRS user obtains her phone number she registers her current street address with the 911 location server – through the VRS provider of her choice.

• VRS provider obtains user phone number from the Central DB (or its local database if available) and routes call to the 911 service provider for delivery to the appropriate PSAP and interprets, the emergency call for the user & 911 operator.

• If caller is not pre-registered, VI will need to obtain location information from caller, load address information in real time prior to routing the 911 call.

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Back Up

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Video Relay Service(from 1/6/2006 CSD Presentation to NANC)

InternetInternetPSTNPSTN

Deaf or Hard of Hearing ASL User

Hearing UserCommunications Assistant(Video Interpreter)

ASL CommunicationBetween Deaf and CA

Voice CommunicationBetween Hearing and CA

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VRS Provider B

Today Multiple VRS Providers operateMultiple Separate Databases

There are an estimated 100,000 video phones in use today by Deaf & Hard of Hearing consumers.

Each provider maintains a separate and closed database of its users and devices, including their unique IP address on the Internet.• Some provider assign proxy numbers, some assign extensions, others

provide Toll Free numbers or none at all – dialing methods vary depending upon provider and device.

Because these databases are closed and do not communicate with each other end users are restricted from being able to easily dial each other.VRS Provider A

VRS Provider C

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Simple Solution for Creating Dialing Parity

1. VRS providers assign NANP geographic numbers to deaf users. (providers can obtain numbers through commercial agreements in the same manner that VoIP service providers do today)

2. New secure 3rd Party database containing current IP address & telephone numbers of VRS users.

3. Each VRS provider must keep the Central Database current with end user IP address & telephone number using a secure Dynamic DNS interface.

4. The 100,000+ existing video phones remain the same, communicating their current IP address to the provider of the device as they do today.

Telephone numbers to IP

address

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NPAC Proposal has significant challenges• The NPAC is not a call processing database and will not contain

IP addresses• Instead the NPAC will have URIs,

e.g. 7948675309@vrssp1.com• The NPAC downloads the URIs to a 3rd party database, which

VRS companies would have to interface with. • On calls to VRS users other than their own, the calling VRS SP

must – Query the 3rd party database for the URI– Query DNS to resolve the URI to the IP address of the serving VRS SP– Send the SETUP message to the serving VRS SP for forwarding or redirection

to the called VRS user

• New development in the NPAC is required

• VRS SPs must – Work through the company providing telephone numbers to provision the

NPAC– contract with a database provider and meet their query interface– Plan to redirect or forward calls originated by other providers