[SIPForum-techwg] Question about early dialog

[mike xu]

Hi Dale,

Thank your for your recommendation! These sip race examples are really
useful for me to understanding sip early dialog, dialog, dialog state
much more.
For the INVITE-with-Replaces case, it seems I needn't take care of it
currently :-)

Thanks again,
Mike

On Nov 7, 2007 11:05 PM, Dale Worley <dworley at pingtel.com> wrote:
> On Wed, 2007-11-07 at 10:43 +0800, mike xu wrote:
> > Do you know that are there any flowchart of multiple early
> > dialog/dialog creation/conversion/termination for reference? It will
> > be great appreciated if there are any flowcharts exist :-)
>
> A single flowchart is not a good model for the situation.  A better
> model is a collection of flowcharts, one flowchart controlling the state
> of each dialog.  An incoming response with a previously unseen to-tag
> causes a new flowchart to be instantiated.  Responses with previously
> seen to-tags cause state transitions in their corresponding flowcharts.
> A final response for any dialog initiates the process of terminating all
> the other dialogs.
>
> A decent introduction is draft-ietf-sipping-race-examples-04.
>
> One related issue that we've discovered even established products
> sometimes get wrong is keeping track of all the dialog identifiers so
> the phone can respond correctly to an INVITE-with-Replaces.
>
> Dale
>
>
>