El Martes 07 Abril 2009, Klaus Darilion escribió:
Alice OBP Proxy/Registrar Bob
----- REGISTER ---> ---- REGISTER + Path -->
<----- INVITE --------<---- INVITE ------ <----- INVITE + Route --
^^^^^^Here at this point the OBP forwards the request to Alice based on the RURI. The RURI is the URI which Alice provided in the Contact header of the REGISTER.
I understand your point. BTW, couldn't the OBP change the REGISTER Contact address? This is:
Alice NAT OBP Proxy/Registrar Bob
----(1) REGISTER -> --(2)- REGISTER + Path -->
<----- INVITE -------- <---(4)- INVITE --- <--(3)- INVITE + Route ---
(1) REGISTER sip:... Contact: sip:alice@ALICE_PRIVATE_IP
(2) REGISTER sip:... Contact: sip:alice@ALICE_PUBLIC_IP Path: sip:OBP
(3) INVITE sip:alice@ALICE_PUBLIC_IP Route: sip:OBP
(4) INVITE sip:alice@ALICE_PUBLIC_IP
Thus, there is the option to add the received parameter to the Path header. Then the OBP can derive the public IP:port from the received paramter in the Route header.
Yes, that would be the most ellegant solution since it would allow the OBP setting the destination URI:
$du = "sip:ALIC_PUBLIC_IP"
and creating an INVITE as follows:
INVITE sip:alice@ALICE_PRIVATE_IP
In this way, Alice would receive an INVITE with RURI matching *exactly* the Contact she used during registration.
The question now is: Do I have to manually parse the route header, extract the received parameter and set $du, or is there somewhere a function which does this all?
Good question! :) However, I expect you can use the string transformations to parse it.
Interesting subject :)