27 Feb
2009
27 Feb
'09
7:30 p.m.
-----Original Message-----
From: sip-implementors-bounces(a)lists.cs.columbia.edu [mailto:sip-
implementors-bounces(a)lists.cs.columbia.edu] On Behalf Of Iñaki Baz
Castillo
Sent: Friday, February 27, 2009 4:59 AM
The short answer is you don't. Hardly anyone uses/encodes/looks-for the phone-context
param in practice (and not many folks use the Tel: URI scheme either, btw - they just
encode it in a sip scheme).
As for the user=phone, it's been a major source of confusion for folks since many
devices don't encode it (because as you note they have no idea if it's a telephone
number or just a username string of digits). In practice what happens is the
"proxies" often treat the username portion as a phone number if it's
comprised of digits or looks like an E.164, regardless of the user=phone param. So far
that's worked ok, but it may lead to problems someday.
-hadriel
> We have at least two cases now where an
update to the RFC added
> important MUSTs:
>
> - Tel uri - phone-context is now required, which affects all SIP
> devices using SIP uri with user=phone
> regardless if they use a Tel: URI.
Sincerelly I can't understand the usage/requeriment of "user"
parameter. How would detect a phone if the dialed number is a PSTN
number or an extension? For example:
- 1004 is a short number in Spain (Telefonica)
- 2002 could be a domain user
How