[OpenSER-Users] Revealing Number Dialled

[Iñaki Baz Castillo]

El Viernes, 25 de Enero de 2008, Jon Farmer escribió:

> I now want to provide inbound service from other
> telephone numbers to these registed users and want to
> be able to put the number dialled into the SIP header.
> However I am unsure how to represent this in the SIP
> message. Can anyone help me?

The original dialed number should appear in "To" header always (except if a 
not SIP compliant node modifies it, but it shouldn't occur).

This is: If your proxy receives a call from a PSTN gateways to 12345678 number 
the INVITE is something like:

  INVITE sip:12345678 at IP_proxy SIP/2.0
  From: <sip:00112233 at IP_gateway>
  To: <sip:12345678 at IP_proxy>

Later, your proxy will do a ENUM query or any other mechanism in order to map 
that PSTN number to a local SIP AoR, so the INVITE will become:

  INVITE sip:client001 at IP_proxy SIP/2.0
  From: <sip:00112233 at IP_gateway>
  To: <sip:12345678 at IP_proxy>

After that, probably the proxy will look for the location of that AoR so it 
will do a "lookup()". If that AoR is registered the INVITE will become:

  INVITE sip:client001 at IP_client001 SIP/2.0
  From: <sip:00112233 at IP_gateway>
  To: <sip:12345678 at IP_proxy>

As you see, the "To" hasn't been modified so it will arrive to the user 
(client001). For example some UACs as Twinkle show the "To" header.
Of course, most of the deskphones just show the "From" header in the screen.


-- 
Iñaki Baz Castillo