[asterisk-dev] ACK - wrong URI?

[Chris Maciejewski]

Hi,

It seems to me Asterisk (1.6.1) is wrongly using "Contact" header from
"200 OK" instead of original INVITE's URI when sending ACK to "200 OK"

My scenario:

1. Asterisk sends INVITE to 442088462718 at example.com:

INVITE sip:442088462718 at example.com SIP/2.0
From: "John Smith" <sip:NA@{some_ip_2}>;tag=as7ff91d10
To: <sip:442088462718 at example.com>
Contact: <sip:NA@{some_ip_2}>
{body/some headers omitted}

2. 442088462718 at example.com replies with 100, 180 and finally:

SIP/2.0 200 OK
From: "John Smith" <sip:NA@{some_ip_2}>;tag=as7ff91d10
To: <sip:442088462718 at example.com>;tag=2UBy3tD90HyrH
Contact: <sip:{__CONTACT_IP__}>
{body/some headers omitted}

3. Asterisk sends ACK with {CONTACT_IP} from "200 OK", rather than
sip:442088462718 at example.com as in originaly INVITE:

ACK sip:{__CONTACT_IP__}:5060 SIP/2.0
Max-Forwards: 69
From: "John Smith" <sip:NA@{some_ip_2}>;tag=as7ff91d10
To: <sip:442088462718 at example.com>;tag=2UBy3tD90HyrH
Contact: <sip:NA@{some_ip_2}>
{some headers omitted}

Is it a bug in Asterisk, or is it RFC 3261 complaint to use "Contact"
from "200 OK" as ACK's URI?

Best regards

Chris