E.212 ENUMService Type Definition
E.212 Parameters for the "tel" URI
Edward Lewis
NeuStar
IETF 68 ENUM WG meeting
19 March 2007
ed.lewis@neustar.biz
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Back-to-Back Items
• draft-lewis-enum-enumservice-e21200.txt
– To register "E2U+E212" as enumservice
– Indicates NAPTR has ITU E.212 infomation
• draft-lewis-enum-teluri-e212-00.txt
– To define parameters in tel: for E.212
19 March 2007
ed.lewis@neustar.biz
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Plans for the two
• Go over comments received so far, get
more while here
• Edit the documents in the coming
week(s) post IETF68
• Submit again as directed (WG or not)
19 March 2007
ed.lewis@neustar.biz
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E.212 for IETF'ers
• E.212 is an ITU document/standard
defining meta-data for a mobile-phone
telephone number
– MCC (Mobile Country Code)
– MNC (Mobile Network Code)
– MSIN (Mobile Subscriber Identification #)
– IMSI (International Mobile Subscriber
Identity) - the concatenation of the other 3
19 March 2007
ed.lewis@neustar.biz
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A diagram
MCC
MNC
MSIN
IMSI
MCC - 3 digits
MNC - 2 or 3 digits
MSIN - up to 10 digits
IMSI - up to 15 digits
19 March 2007
ed.lewis@neustar.biz
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Why IETF documents?
• This is about ENUM
– Wanting to store the ITU-defined
parameters in ENUM
– This isn't so much about E.212, 'cept that
that is the "payload"
19 March 2007
ed.lewis@neustar.biz
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draft-lewis-enumenumservice-e212-00.txt
• First, it's a -00 individual, happy to make
it a WG document
• Fills in an ENUM service "application"
• E2U+E212 means the NAPTR RR has
a tel: URI (with extensions in the other
draft)
19 March 2007
ed.lewis@neustar.biz
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Comments on that one
• Would like a good use case
– Fair enough, the draft is minimal and am
happy to add that. Still in the process of
writing it.
• Is it worth getting a non-SIP ENUM
extension defined?
– Suggestion to use an experimental (x-) but
really want a "real" definition
19 March 2007
ed.lewis@neustar.biz
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Use case
• With number porting, can't tell the
carrier by the number alone
– Knowing the receiving operator of a call
could impact business decisions
• In Softswitch draft "...interconnection only with
trusted carriers"
– For IM knowing the MCC+MNC can
determine the receiving server name
19 March 2007
ed.lewis@neustar.biz
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More comments
• What about "aux-info:e212"?
– Although workable, a few reservations
• We/WG don't have other "aux-info's" in mind, I
don't like to generalize from a single case
• E.212 is subjectively significant enough to
stand on its own, and is reliant on an external
(ITU) definition
• Linking in other (unknown) types would likely
slow this process
19 March 2007
ed.lewis@neustar.biz
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First doc question to WG
• Should this be adopted as WG item?
– What is missing from the application and
supporting document?
• Sub-note: I couldn't find a reliable "how
to" to follow when submitting these
drafts, so I "undercut" the submission
19 March 2007
ed.lewis@neustar.biz
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draft-lewis-enum-teluri-e21200.txt
• This document defines parameters for
the tel: URI to hold the E.212 data
– In the spirit of RFC 4694, but for different
data
• Four parameters are defined, as per
earlier slide (MCC, MNC, MSIN, IMSI)
19 March 2007
ed.lewis@neustar.biz
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My goal
• I am interested in retrieving the MCC
and MNC for a telephone number via
ENUM
• The draft includes MSIN and IMSI
parameters for completeness
19 March 2007
ed.lewis@neustar.biz
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Comments
• This draft ought to go to IPTEL
– No response to that yet from me
• What's E.212?
– Should this draft explain it or just refer to
the ITU document (now freely available)?
– When I prepared the draft, I went for not
including an explanation but can be
convinced otherwise
19 March 2007
ed.lewis@neustar.biz
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More comments
• Need an illustrative use case
– Working on that, went for brevity in the -00
• The ABNF is wrong
– A few pointed this out, you are all right, I'll
fix that
• The URI is wrong
– Sorry - sigh, I wrote the draft on an
airplane and it shows ;) (Goes for the
ABNF too.)
19 March 2007
ed.lewis@neustar.biz
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Yet more comments
• MCC+MNC xor IMSI?
– Should the syntax require either both MCC
and MNC be present or the IMSI be
present?
– My response is - that's the probable use
case, but does this have to be encoded in
the syntax rules? I prefer to let the syntax
be freer than the use
19 March 2007
ed.lewis@neustar.biz
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And more comments...
• Isn't it unwise to have the IMSI, MSIN,
and maybe even the MCC and MNC in
a public database?
– I'd agree with that, but the drafts are just
providing a means to put this in ENUM and
not saying that the data would be public
– Not all DNS servers are on public networks
19 March 2007
ed.lewis@neustar.biz
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Second doc questions
• Should this be an ENUM WG doc or go
ask IPTEL WG to adopt this?
19 March 2007
ed.lewis@neustar.biz
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Well, I'm out of slides
• Discussion?
19 March 2007
ed.lewis@neustar.biz
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19 March 2007
ed.lewis@neustar.biz
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