enum: what does it mean?what does it matter? tmdentonvancouver, bcmay 4, 2004

ENUM: What does it mean?What does it matter?

TMDenton Vancouver, BC May 4, 2004

ENUM: What does it mean? tmdenton.com

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Introduction• Why is ENUM?

• What is ENUM?

• What it is not

• The politics of ENUM

• Getting a delegation in North America

• Privacy concerns


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Telephones and computers• There are about 2 billion telephones in the

world, fixed and mobile, 1 billion landline and 946 million mobile (March 2003)

• 157 million computers hosts

• 588 million personal computers• Source “ITU Statistics at a glance”

• Every computer has an address; because we remember names better, domain names translate into IP addresses

• Telephone numbers connect telephones.


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Connecting keyboards to dial pads

• ENUM is but one way of connecting two vast installed bases of equipment

• Another way is to replace all existing phones with qwerty keyboards, e.g. Trio 270

• VOIP is the coming wave of change

• ENUM allows the directory system to catch up with the rest of the changes in signal transmission.

• The older SS7-based look-up system is by-passed.


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What is ENUM?• ENUM is a standard of the Internet Engineering

Task Force (IETF)• which turns telephone numbers into a domain

name, for example - 613-237-5335• And allows inquires through the Domain Name

System…• where a record, called the Naming Authority

Pointer record, is kept.• The Naming Authority Pointer (NAPTR) record

defines what services a person wants out of the system.


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The core problem

• How do you find a service on the Internet if all you have is a Telephone Number ?


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ENUM• The ENUM system allows the domain name system to

transform (map) telephone numbers into domain names.• Telephone numbers are referred to as “E164” numbers, after

the ITU standard which specifies them.

• The resulting name is looked up in the DNS (domain name system).

• The look-up returns a set of records referred to as Naming Authority Pointer (NAPTR) records.

• The NAPTR records define the services the person has entered into the record.


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The Domain Name System• The Domain Name System, or DNS, is designed

to ensure that each Internet address is globally unique and corresponds to a distinct numeric value.

• The system resolves a domain name, such as “www.cira.ca,” into a unique "IP address" -- a numerical name containing four blocks of up to three digits each (such as 198.41.0.52), which points to a single location on the Internet.

• The DNS was designed primarily as a mnemonic device to help people remember the “addresses” of Web pages more easily.


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The Domain Name System 2• The DNS system consists of three components:

• DNS data (called resource records), • servers (called name servers), and • Internet protocols for fetching data from the servers

• The billions of resource records in the DNS are split into millions of files called zones. Zones are kept on authoritative servers distributed all over the Internet.

• The creation and management of domain names is worked out in the Internet Corporation for Assigned Names and Numbers (ICANN).


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What ENUM is and is not• ENUM is not

• A directory, or a change in telephone numbering• A search service• A transport service• A telephony service or a voice encoding protocol

• ENUM is• A partial mapping of e.164 numbers to domain

names, whose record defines a set of services.

• ENUM’s goal is that one party should be able to look up information in the DNS, which another party has stored in the DNS.


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ENUM’s potential• ENUM offers Internet-based users to select from a

range of services available for communicating with another person when all he knows is a telephone number.

• Spans both the legacy telephone and new VOIP networks

• Telephone number becomes the only thing to remember

• Supports all dialling plans• simplifies call routing and number portability for phone

companies• One number for life?


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What is the problem to be solved?

Intra-EnterpriseCalling(40%)Employees

Inter-EnterpriseCalling(40%)Typically

Other

ENUM Solves the problem of cross domain or “Inter-Enterprise” call-capture. 80% or more of Enterprise calls can go all IP.

Toll Calls are a $110 Billion revenue stream. $987 per Business line per year in toll charges (source FCC)


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The Politics of ENUM• The Internet Engineering Task Force developed

ENUM as a standard (formerly RFC 2916, now RFC 3761) www.ietf.org

• The ITU has control over the use of telephone numbers, and this control is delegated to national administrations. Using telephone numbers requires their permission.

• The IETF is a volunteer organization with no membership, open to participation by all, and works by mailing lists.

• The ITU is a treaty-based organization dating back to the foundation of telegraphy.


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Authority to include telephone numbers in the system

• The ITU-T wants to be sure that national governments have authorized their country’s telephone numbers to be placed in the official E164.arpa root.

• Problem: North America and the Caribbean belong to Country Code 1 (17 countries). Normally this would mean unanimous agreement among 17 countries • Smaller countries suspicions of the implications• Lack of interest or awareness

What are our alternatives?


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The ENUM Delegation Tiers

In order to get the official E164 delegation from the ITU, a country must apply for it.


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A hierarchy of Tiers• If E164.arpa is to be the ultimate root of authority over

ENUM, then the ITU wants ultimate authority over Tier 0, the “root”.

• Below Tier 0 lies the Tier 1 which is under “national” administration

• That is the North American Numbering Plan Administration (NANPA) for CC1.

• How do we assure national policy is followed when “country code 1” is international?• This has already been worked out in telephone numbering • The DNS structure for Canada and the US is different:

dot ca and dot us


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ITU and IAB decide…• The Internet Architecture Board (IAB) selected

a Dutch non-profit registry, RIPE NCC to operate the Tier 0 registry.

• Requests for delegation are checked by the ITU• ITU determines what is and is not a country• And what is or is not a valid country code• And whether a “country” has asked for delegation• Rule of unanimity for country code 1

• Delegations proceed only if ITU says so• ITU has control of the contents of E164.arpa


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A structure for ENUM in CC1• The US is developing an ENUM LLC (limited

liability company) to receive delegation and manage a competition for a national US registry

• Canada has to figure out a) how to get national policy respected and b) sort out who will be the national registry for

Canadac) How the national industry will work

• Enter Skinny Tier 1: a recipient of delegation from the ITU which hands off the registry work to “national” administrations in North America.


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Progress so far• In Canada we have established a working

group under the CRTC to develop ENUM policy - http://www.crtc.gc.ca/cisc/eng/CSCNT53.HTM

• Participants (telcos, cable, CIRA, registrars) support • immediate delegation of 1.e164.arpa on an interim basis to

CC1 • the right of individual NANP nations to decide whether or not

they opt into the use of ENUM• regulatory requirements of each nation and the operational

requirements of ENUM service providers in each nation should be satisfied


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Many issues remain• Will the system conform to how the DNS works

now? Or will it reflect how the numbering system works?• Breaking the NAPTR records between Tier 1 and Tier 2• Moving whole record over to the registry, when?

• How will we choose a Canadian provider?• Use the US registry?• Develop a new Canadian registry?• Use CIRA?

• Is ENUM a consumer product or a system improvement that will be largely invisible to the consumer?


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Privacy• No one wants their personal information on a

database that anyone in the whole world can look up.

• ICANN has had large problems with the Whois registry for this reason.

• Canada will almost certainly adopt the “called party control” model where the publicly accessible record shows the minimum of information to allow the system to work, e.g.a SIP address.


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ENUM resourcesIn Canada: http://www.enumorg.ca

http://www.crtc.gc.ca/cisc/eng/CSCNT53.HTM

In the USA: http://www.enum.org

ENUM Basics – Internet Protocol Journal

http://www.cisco.com/warp/public/759/ipj_5-2.pdf

ENUM core protocol

http://www.ietf.org/rfc/rfc2916.txt

ENUM charter

http://www.ietf.org/html.charters/enum-charter.html

IETF-ITU liaison statement

ftp://ftp.isi.edu/in-notes/rfc3026.txt

Other ENUM Web Sites:

International telecommunications union

http://www.itu.int/infocom/enum/

CyberTelecom

http://www.cybertelecom.org/enum.htm


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Thank you• www.tmdenton.com

enum: what does it mean?what does it matter? tmdentonvancouver, bcmay 4, 2004

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