On 02/03/2010 04:44 PM, IƱaki Baz Castillo wrote:
This is a re-INVITE and the UA (MY_SBC_PROXY) replies a 200 with the natted Contact (as usual). Then the PSTN_PROXY server creates the ACK by setting such private SIP URI as RURI. This is incorrect, this RURI *MUST* be the remote target set in the initial INVITE/200 (the Contact the UA received when the dialog was established). This remote target cannot change within a dialog (as Alex and me have explained in this thread).
I do not have statistics, but anecdotally speaking, I have encountered this problem so often and had to work around it by re-fixing the Contact in the sequential INVITE or reply to it that I did not even know it was an incorrect behaviour! I suspect it is rather common.