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

[Olle E. Johansson]

Tzafrir Cohen wrote:
> On Thu, Apr 28, 2005 at 05:15:34PM +0200, Olle E. Johansson wrote:
> 
>>Steve Underwood wrote:
>>
>>>Hi,
>>>
>>>I raised this with Mark ages ago, when I started putting Chinese into 
>>>IAX2 messages. I thought it should be specified that all text is Unicode 
>>>in UTF-8 form, but he seemed pretty indifferent to specifying anything.
>>>
>>>There is no need to have ASCII + UTF-8. ASCII is a subset of UTF-8, so 
>>>they are fully compatible. Its only when you have 8 bit sets, like the 
>>>PC ones, that compatibility is an issue. Just define that all strings in 
>>>IAX2 are UTF-8, and that is the end of it.
>>>
>>
>>...yes, I'll admit that is an easy way out. But we still need to handle
>>conversion to ISO8859-1 caller ID's 
> 
> 
> Where is ISO-8859-1 used? What about names in non-latin1 charsets?
> What about my name, for instance?
Guess we have to find the PSTN standard. Anyone that knows where to find 
exact information on character sets for caller ID names over PSTN lines?

> 
>>and find a way to do pattern 
>>matching and how to use "." and "@" in IAX to call SIP uri's - there are 
>>many things to consider. (The @ in an IAX2 dialstring separates 
>>extension from context...)
> 
> 
> This is not a problem. See utf-8(7). An ASCII byte in a UTF-8 stream can
> only be part of a single-byte ascii character. This is not UTF-16.
> 
You misunderstand me, I'm talking about how Asterisk treats various 
constructs that will break if we are about to implement only ONE utf8 
dialstring/extension all over Asterisk. The pattern matching in the 
dialplan needs to change, the IAX2 protocol/dial string and a lot of 
functions in the channels that strip characters from the dial string 
that is not important in PSTN dialling, but are really important in SIP 
uri's.

/O