Transcript VoIP H.323 - enumorg.ca

Industry Canada
Elephone NUmber Mapping
(ENUM)
T
Bob Leafloor
Colman Ho
Peter Chau
Industry Canada
January 2003
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Industry Canada
Disclaimer
The views, thoughts and information contained in
this presentation are solely intended assist in
opening a dialogue on how best to proceed with
ENUM in Canada
These views, thoughts and information do not
necessarily represent views, policies, opinions or
understandings of Industry Canada
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Industry Canada
What is ENUM?
ENUM is a protocol developed by the IETF (RFC
2916) that enables:
• End-user Subscriber Services
• subscriber defined preferences for incoming
communications
• Network to Network Services
• network elements to find services on other network
elements using only a telephone number
• Enhanced SPAM Services
• ENUM could become the worlds largest database of active,
legitimate email addresses –SPAM gold mine?
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Industry Canada
Why ENUM?
An end-user service that specifies alternative
contacting methods for that
end-user
An important integrator of the PSTN, the
Internet and other IP based networks
Facilitates terminating calls from other networks
to IP based networks.
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Industry Canada
ENUM 3 Step Process
1. Transform the telephone number into an ENUM
DNS name
2. Query the DNS to resolve that name and retrieve
information (NAPTR RRs) that have been
associated with the telephone number
3. Choose a service from the DNS NAPTR response
on the various types of services (including order
& preference) associated with the telephone
number
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Industry Canada
Choose a service from the DNS response
The ultimate choice of contact
rests with the sender
Choose
ENUM
Database
The result of an ENUM DNS query is the NAPTR records,
which specify the alternative methods of contact with their
order of processing and preference
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Industry Canada
Points of Consideration
•
ENUM is specified in IETF RFC 2916
•
RFC 2916 specifies a unique one-to-one bidirectional mapping algorithm between E.164
telephone numbers and DNS names
•
RFC 2916 specifies e164.arpa to be the ENUM
DNS Name Space Root
•
Therefore NAPTR information rooted outside
e164.arpa is not ENUM
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Industry Canada
Points of Consideration
•
The ITU-T as part of it’s E.164 responsibility is
cooperating with the IETF on ENUM
•
Some ITU Member States oppose the use of
e164.arpa as the ENUM root
•
A final decision has yet to be made on the root
within ITU
•
E164.arpa is being used for the ENUM trials, in
accordance with the ITU interim procedures
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Industry Canada
Points of Consideration
•
Draft procedures at the ITU require that ITU
Member States (countries) opt-in to ENUM
before any DNS names corresponding to the
E.164 telephone numbers under that countries
jurisdiction can be added to the ENUM domain
space
•
Canada has yet to reach a decision as to whether
or not to opt-in
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Industry Canada
Points of Consideration
•
Industry Canada is the Canadian ITU
Administration and hence the opt-in/opt-out
authority from an ITU perspective
•
The US has essentially decided to opt-in
•
Since CC 1 is a shared country code, a US opt-in
has implications for Canada and for other CC 1
members
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Industry Canada
Points of Consideration
•
The ITU draft procedures will remain draft until
the e164.arpa issue is resolved
•
The application of ‘ENUM’ technology to
networking problems, or to enable new network
features can be dealt with through existing
processes
•
ENUM Services could potentially facilitate SPAM,
so far this has not been discussed
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Industry Canada
Points of Consideration
• The ENUM domain name space will be organized
in tiers, likely three tiers 0, 1, and 2
• Tier-0, the ENUM domain name space root, would
be administered by the ITU-T/Ripe NCC
• Countries would opt-in or opt-out at the Tier-0 level
• The Tier-0 name server would have ‘NS’ (Name
Server) records for the Tier-1 name server(s) of the
opted-in countries
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Industry Canada
Points of Consideration
• The organization below Tier-0 for countries
opting-in would be their responsibility
• This would include:
• Administration
• Operation
• Competition
• Privacy/Security, etc.
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Industry Canada
Points of Consideration
• Industry has, at least, business interests in
ENUM?
• Industry Canada interests include Telecom
policy, privacy, security, etc., etc.
• CRTC interests include Telecom regulation,
numbering, etc., etc.
• CIRA is responsible for the DNS name space
under ‘.ca’, including the dispute resolution
process for that domain name space
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Industry Canada
Points of Consideration
• ENUM Hijacking occurs when the assignee
of a complete ENUM domain name is not the
assignee of the corresponding E.164
telephone number
• Administration of E.164 telephone numbers
and ENUM domain names are likely to be
done separately
• Should CIRA be responsible for the DNS
name space under e164.arpa corresponding
to Canadian E.164 telephone numbers?
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Industry Canada
Points of Consideration
• Country Code 1 (CC 1) being integrated is a
special case
• If the ‘NS’ delegation from Tier-0 for CC 1 is
at the ‘1’ level then it needs to point to a single
Tier-1 name server for all of CC 1
• If the ‘NS’ delegation from Tier-0 for CC 1 is
at the ‘1+NPA’ level then it can potentially
point to a separate Tier-1 name server for each
NPA of CC 1, as per the following example
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Industry Canada
Tiered Structure – An Example
Provider
Registry
Registry
Tier-2
Tier-1
Tier-0
Stores a list of service
specific internet addresses
in the form of URI’s in a
DNS resource record called
NAPTR for each subscriber
Returns the full list of
Internet addresses
associated with the E.164
number being queried
Directs the DNS
query to the
customer’s Tier-2
providers
An NS record is
provided for each
subscriber’s
telephone
number
Directs the DNS
query to the
countries Tier-1
registries
An NS record is
provided for
each Tier-1
1+NPA registry
National
ITU/Ripe NCC
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Industry Canada
US Forum Perspective
•
The US ENUM Forum (www.enum-forum.org) is
a US industry lead group developing a proposed
US implementation strategy for ENUM
•
The Forum has developed document 6000_1_0 a
comprehensive proposed set of implementation
specifications
•
The Forum is currently working on proposals for
the Tier 1 Contracting Entity and on
Architectural Alternatives
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Industry Canada
US Forum Perspective
•
For Tier 1 Contracting they are
considering:
• Government Procurement
• Industry Limited Liability
Company
•
For Architectural Alternatives they are
considering the five following
alternatives:
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Industry Canada
US Forum Perspective - Architecture
Proposal
• Five Possible Solutions:
• Single Tier 1 for all NANP countries
• Single Tier 1 in US
• With delegation from Tier 0 by 1+NPA
• With delegation from Skinny Tier 1
• Multiple Tier 1 operators in US
• With delegation from Tier 0 by 1+NPA
• With delegation from Skinny Tier 1
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Industry Canada
US Forum Perspective
Single Tier 1 for NANP Countries
• Assumes:
• All of country code 1 is delegated to a single Tier 1
• All participating NANP countries can/will form a
single contracting entity
Tier 0
Tier 1
Tier 2
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Industry Canada
US Forum Perspective
Single Tier 1 for US
• Requires either delegation from Tier 0 by
NPA or Skinny Tier 1
Tier 0
Tier 0
Delegation of country code 1
Delegation by NPA
Skinny Tier 1
Delegation by NPA
US Tier 1
US Tier 1
Tier 2
Tier 2
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Industry Canada
US Forum Perspective
Multiple Tier 1 Operators in the US
• Assumes:
• US NPA’s are delegated to multiple tier 1 entities from
Tier 0; or
• All of country code 1 is delegated to a single skinny Tier 1
Tier 0
Tier 0
Delegation of country code 1
Skinny Tier 1
Delegation by NPA
Delegation by NPA
US Tier 1s
US Tier 1s
Tier 2
Tier 2
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Industry Canada
US Forum Perspective - Summary
No consensus on architectural alternatives
• Any solution which involves the delegation of
country code 1 from Tier 0 will require
agreement from all 19 NANP countries
• Delegation of US NPAs from Tier 0 may
require negotiation with Tier 0
• How many registries should operate for those
NPAs in the US?
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Industry Canada
Canadian Perspective
•
Industry Canada has been following ENUM for
some time now
•
A working group was established under TSACC,
a presentation was made to CSCN, etc.
•
The US picture was initially unclear and Industry
Canada, TSACC and industry were essentially at
a wait and see
•
But that was then and this is now…..
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Industry Canada
Canadian Perspective
•
Proposed ENUM service offerings in Canada
should originate from industry!
•
When the US goes forward on ENUM, we need to
recognize that:
•
•
Their selected architectural alternative will
have implications for Canada as we share the
same Country Code
If the US service is a success, Canadian
subscribers may ask why there is no Canadian
service
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Industry Canada
Canadian Perspective
•
Canadian ENUM interested parties include:
•
•
•
•
•
Industry
Industry Canada
TSACC
CRTC
CRTC/CISC Working Groups
•
•
•
•
Committee on Numbering (CSCN)
Network Working Group
CIRA
Customers
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Industry Canada
Canadian Perspective
•
Some items for our consideration include:
•
The Tier-1/2 structure, administration, and operation
•
Location requirements (if any) for Tier-1/2 operators
•
Interfacing with other members of CC 1 on implementation
•
How 1+800 etc., for Country Code 1 should be handled
•
How to keep ENUM transparent to NANP/NANPA and vise versa
•
DNS security requirements for ENUM
•
Privacy, Confidentiality, Integrity, Availability, and Identification
and Authentication requirements for ENUM
•
What threats and vulnerabilities may ENUM be subject to
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Industry Canada
Elephone NUmber Mapping
(ENUM)
T
Thank you
Bob Leafloor
Colman Ho
Peter Chau
Industry Canada
January 2003
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