Transcript Mr. Vincent Humphries

Introduction to
ENUM
Vince Humphries
European Radiocommunications Office
[email protected]
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Overview
2
• Purpose
• Main features
• Scope
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Purpose…
3
Original purpose:
– Enable VoIP clients to be identified and reached
via commonly-used name — end user’s telephone
number
…Purpose
4
Purpose has evolved:
– Enable any communications application to
determine availability of (Internet-based)
communications services
• telephone number used as easily recognised
“front end” to various communications services
used by end user
• telephone number used as look-up key to find
available communications services
– Electronic business card directory
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Main Features…
5
Telephone numbers are translated to Internet
universal resource identifiers (URIs)
URIs identify communications service:
– mailto:[email protected]
– sip:[email protected]
– ftp://ftp.ero.dk/vince-docs
– h323:[email protected]
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…Main Features
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Details of translation from telephone number to
URI specified in naming address pointer
records
Naming address pointer records:
– are stored in Internet domain name system
– may be accessed by client applications
– may be used to obtain list of URIs
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…Main Features
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URIs may be used for connecting to
communications service associated with
telephone number
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Example
8
Naming address pointer record, formatted
according to IETF RFC2915 and RFC2916:
TELEPHONE NUMBER +351 217211000

$ORIGIN 0.0.0.1.1.2.7.1.2.1.5.3.e164.arpa
IN NAPTR 100 10 "u" "E2U+sip"
"!^.*$! sip:[email protected] !"
IN NAPTR 102 10 "u" "E2U+mailto" "!^.*$! mailto:[email protected] !"
order
preference
flag indicating
terminal look-up
service
substitution
expression
replacement
domain name
Scope
9
Any E.164 telephone number can potentially be
used in ENUM
• geographic numbers, mobile numbers,
•
•
personal numbers
freephone numbers, premium rate numbers
global network numbers, global service
numbers
Any Internet URI can potentially be used in
ENUM
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