Fwd: [CAP] ASN.1 Formatting?

[Art Botterell <acb@incident.com>]

[Again, sorry for spamming the whole TC... Allen/Rick, any progress 
on getting the other SC's their lists?]

Quoted below is a note from the CAP Working Group's email list 
(archive at <http://www.incident.com/pipermail/cap-list/>) about 
potential benefits of framing CAP in ASN.1 terms.  As I note, I've 
just recently begun to get oriented to ASN.1, but it seems compatible 
with our XML focus.  Can anyone offer any insights or comments?

- Art


>To: cap-list@incident.com
>From: Art Botterell <acb@incident.com>
>Subject: [CAP] ASN.1 Formatting?
>Date: Thu, 24 Apr 2003 07:08:44 -0700
>
>Friends -
>
>What appears below is an ASN.1 portrayal of the current (v. 0.7) CAP 
>message format, generated by running our existing draft XML schema 
>through an automated conversion tool.
>
>From the ASN.1 homepage <http://asn1.elibel.tm.fr/en/index.htm>: 
>"Abstract Syntax Notation number One (ASN.1) is an international 
>standard that aims at specifying data used in communication 
>protocols. It is a powerful and complex language: its features are 
>designed to describe accurately and efficiently communications 
>between homogeneous or heterogeneous systems."
>
>What's interesting about ASN.1 is that its abstract format with 
>defined mappings to various real-world encodings, including XML. 
>What this means is that a message format from ASN.1 can be 
>translated precisely into XML and also into several specialized 
>encodings such as the Packed Encoding Rules (PER) "for applications 
>that undergo restrictions in terms of bandwidth.These encoding rules 
>describe how the values defined in ASN.1 should be encoded for 
>transmission ( i.e. , how they can be translated into the bytes 
>'over the wire' and reverse), regardless of machine, programming 
>language, or how it is represented in an application program." 
>(From <http://asn1.elibel.tm.fr/en/introduction/index.htm>.)
>
>You'll note below that our current naming convention could be 
>adjusted for improved ASN.1 compatibility by changing all the 
>underscores to hyphens.  Some other issues may arise... our friend 
>Elliot Christian has asked the "asn1xml" working group for their 
>advice.  Still, the interchange seems to be fairly clean.
>
>At this point I'm just getting to know ASN.1 a bit, personally, so 
>I'm not making any recommendation at this point... but I thought it 
>might be worth sharing this for discussion.  Anyone else have any 
>experience, good or bad, with ASN.1?
>
>- Art
>
>
>------------------------------------------------------------
>Generated by xsd2asn1, the XML Schema to ASN.1 translator of France 
>Telecom R&D
>
>Cap-0-7 DEFINITIONS AUTOMATIC TAGS ::=
>BEGIN
>
>IMPORTS
>   AnyURI, Language, DateTime
>     FROM XSD;
>
>-- CAP Alert Message (draft version 0.7)
>Alert  ::= -- NAME AS UNCAPITALIZED -- -- NAME AS UNCAPITALIZED -- SEQUENCE {
>    msg-id -- NAME AS "msg_id" -- UTF8String ,
>    sender-id -- NAME AS "sender_id" -- UTF8String ,
>    password UTF8String OPTIONAL,
>    source-id -- NAME AS "source_id" -- UTF8String OPTIONAL,
>    sent DateTime ,
>    msg-status -- NAME AS "msg_status" -- ENUMERATED {actual, exercise, test} ,
>    msg-scope -- NAME AS "msg_scope" -- ENUMERATED {public, 
>restricted, private} ,
>    auth-code -- NAME AS "auth_code" -- UTF8String OPTIONAL,
>    msg-type -- NAME AS "msg_type" -- ENUMERATED {alert, update, 
>cancel, ack, error} ,
>    msg-note -- NAME AS "msg_note" -- UTF8String OPTIONAL,
>    ref-id -- NAME AS "ref_id" -- SEQUENCE OF UTF8String OPTIONAL,
>    incident-id -- NAME AS "incident_id" -- SEQUENCE OF UTF8String OPTIONAL,
>    info -- UNTAGGED -- SEQUENCE OF info -- UNTAGGED -- SEQUENCE {
>       language Language DEFAULT "en-US" ,
>       event-cat -- NAME AS "event_cat" -- ENUMERATED {geo, met, 
>security, rescue, fire, health, env, transport, infra, other, 
>safety} ,
>       event-type -- NAME AS "event_type" -- UTF8String ,
>       urgency ENUMERATED {ongoing, impending, forecast, past, unknown} ,
>       severity ENUMERATED {extreme, severe, moderate, minor, unknown} ,
>       certainty ENUMERATED {high, moderate, low, minimal, unknown} ,
>       audience UTF8String OPTIONAL,
>       area -- UNTAGGED -- SEQUENCE OF area -- UNTAGGED -- SEQUENCE {
>          area-desc -- NAME AS "area_desc" -- UTF8String ,
>          choice -- UNTAGGED -- CHOICE {
>             polygon SEQUENCE OF UTF8String ,
>             radius SEQUENCE OF UTF8String ,
>             geo-code -- NAME AS "geo_code" -- UTF8String } OPTIONAL} ,
>       target-code -- UNTAGGED -- SEQUENCE OF target-code -- NAME AS 
>"target_code" -- UTF8String ,
>       effective DateTime OPTIONAL,
>       onset DateTime OPTIONAL,
>       expires DateTime OPTIONAL,
>       sender-desc -- NAME AS "sender_desc" -- UTF8String OPTIONAL,
>       headline UTF8String OPTIONAL,
>       event-desc -- NAME AS "event_desc" -- UTF8String OPTIONAL,
>       instruction UTF8String OPTIONAL,
>       info-url -- NAME AS "info_url" -- AnyURI OPTIONAL,
>       image-url -- NAME AS "image_url" -- AnyURI OPTIONAL,
>       audio-url -- NAME AS "audio_url" -- AnyURI OPTIONAL,
>       contact UTF8String OPTIONAL,
>       parameter -- UNTAGGED -- SEQUENCE OF parameter UTF8String } }
>END
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