[OpenSIPS-Users] Help with the dialog module please

[opensipslist at encambio.com]

Hello list,

Does the dialog module define a dialog as from the:

  First INVITE that appears with Call-ID '1234'

...or

  Second INVITE that appears with Call-ID '1234'

I'm asking because if a unauthenticated INVITE arrives the sending
UAC will be forced to send a second INVITE (with a new cseq) that
includes authentication credentials. If the second INVITE with its
auth credentials is accepted, then I assume that the dialog begins.
It therefore follows that the first INVITE will not be included in
the dialog modules table of dialogs, and will be ignored in the
dialog context. Is that right?

What I'm trying to do is set_dlg_flag("20") in the first INVITE and
then read is_dlg_flag_set("20") in the next one. It would be
convenient if the first INVITE began the dialog and the second
INVITE was considered part of the dialog as well. Is this possible?

Can I change some SIP header of the second INVITE to match the
first, so that the dialog module believes them both to be in the
same dialog?

Another question, is there any difference between:

    modparam("dialog", "dlg_flag", 4)
    route {
        setflag(4);
    }

...and

    route {
        create_dialog();
    }

Are they completely interchangeable? Does this make sense:

    modparam("dialog", "dlg_flag", 4)
    route {
        setflag(4);
        create_dialog();
    }

Thanks,
Brian