[Asterisk-Dev] IAX spec: Text formats and character sets

[John Todd]

At 8:48 AM +0200 on 4/28/05, Olle E. Johansson wrote:
>Good morning, bonjour, god dag!
>
>The IAX spec has to be more specific in regards to character sets
>used in various messages.
>
>The numbers and CID names are specified as "ASCII encoded text".
>There's not spec of HTML text format. That assumes ISO-8859-1, 8 bit.
>
>* ASCII is 7 bit only. A-Z
>* As far as I know, Caller ID Name is also ISO 8859-1, 8 bit.
>* SIP is UTF8, meaning I can include not only Swedish ÅÄÖ but almost
>   any character set, except the secret magic runes...
>
>We need to set an Asterisk /IAX2 standard for 
>text frames, "numbers" and caller ID names. 
>Asterisk is more and more becoming an 
>international project and we need to work this 
>out before we've come too far in the
>"all text strings are US ASCII" soup and can't 
>clear this up. I've been working quite a long 
>time with network communication and have carried 
>a large number of Swedish keyboards to US 
>programmers that needed to learn that there 
>where more characters in the world than A-Z and 
>even stranger keyboards (as the participants on 
>Astricon Training in Stockholm quickly had to 
>learn :-) )
>
>I would like to see that Asterisk internally 
>uses two sets of names and phone numbers - one 
>alphanumeric UTF 8 and one ASCII. That way we 
>can handle both SIP and IAX2 and know what kind 
>of object we're handling.
>Right now, the SIP channel happily adds UTF8 
>caller ID names to the CID*name field, or UTF8 
>extensions/phone numers/user names to the called 
>extension field.
>
>Leif Madsen and I have written a proposal that 
>we would like the community to review, called 
>alphaextensions. In this, we try to define a way 
>to add proper handling of international 
>character sets in extensions (a la SIP) without 
>breaking backwards compatibility with the 
>current dialplans and applications within 
>Asterisk.
>
>This proposal is available at
>http://edvina.net/asterisk/alphanumericextensions.pdf
>
>...and we would very much like input on that. 
>This became even more important after browsing 
>through the IAX spec (IAX2 spec? :-) ).
>
>Another quick comment: I think we should format 
>the IAX spec not as an Internet Draft, but as an 
>Informational RFC like the early NFS RFCs, since 
>the wording of the first paragraphs tells us 
>that it will never be published as an IETF draft 
>any way...
>
>/Olle


Olle -
   I can't find anything to argue with in your 
proposal.  The inclusion (well, exclusion) of '@' 
has been a thorn in my side a few times, and 
while I can't speak for the international 
characters (as I rarely use them) I clearly see 
the benefit of the added character expansions for 
those of you in the world who like to add little 
squiggles and dots to your ASCII.  ;-)

   Though it is only a sidebar to your main 
discussion, I especially like the "(prev)" 
concept - that would clean up my dialplans quite 
a bit.

JT