Re: [sip-overload] AD review of draft-ietf-soc-load-control-event-package-08

[Charles Shen <[e-mail]>]

Hi Richard, please see additional questions regarding "tel" URL grouping:

On Fri, Jun 21, 2013 at 7:00 AM, Richard Barnes <[e-mail]> wrote:

> Inline.  Areas of agreement snipped.
>
>
> On Thu, Jun 20, 2013 at 1:40 AM, Charles Shen <[e-mail]>wrote:
>
>> To be clear on this, the ambiguity here is with regard to the <except
>>> domain="..."> case.  In the <one id="..."> case, you just do Tel URI
>>> comparison.
>>>
>>> Thinking on this a little more, it looks like your use of the "domain"
>>> parameter actually breaks with RFC 4745.  According to RFC 4745, there must
>>> be an exact match between the "domain" value provided by the using protocol
>>> and the value in the "domain" parameter.  I can't think of a way that this
>>> document could define a way to extract a domain from a telephone number
>>> that would meet the semantic you seem to be intending.
>>>
>>> So it seems like you need to do one of the following:
>>> 1. Define a rule for how you compute a domain value from a tel: URI.
>>> 2. Define a new element for use under <many> (since <except> lacks an
>>> extension point)
>>> 3. Drop support for excluding phone numbers by domain (you just have to
>>> enumerate the exceptions individually)
>>>
>>>
>> [CS] If we opt for Option 1, can we do the following:
>>
>> a. assume E.164 numbers always start with + sign, so we can use the
>> digits after the + sign (after removing any visual separaters, as in the
>> Tel URL comparison rules) as the presumed domain value.
>> b. for local numbers (numbers that do not start with +), the
>> "phone-context" contains the domain value.
>>
>
> Are you sure that gives you the expressiveness you want?  It doesn't allow
> you to exclude based on an arbitrary prefix.  For example, <except
> domain="+1212"> would not match the URI "tel:[phone]", because the
> "domain" value for that URI would be "12125551212".
>
> It seems like (2) is the option that's most likely to give you what you
> want.  Suggest defining something like a "<except-tel>" element, so that
> you could say something like <except-tel prefix="+1212">.
>

 I am absolutely fine adding another element, but just want to make sure I
indeed understand your concern before doing that.

According to the current texts (paragraph 2, pg.18), when the specified
domain value starts with a "+" sign, it denotes a number prefix, if its
"+1-212", the prefix is "1212" (after removing any visual separaters, as in
the Tel URL comparison rules, this needs to be added explicitly), and this
prefix is used to match numbers (again after removing any visual separaters),
therefore, it should match the number "1212551212" in the tel URL
tel:[phone].

Did I miss something here? thanks!

Charles