[Serusers] NOTIFY header construction for mid-dialog presence event package

Vaclav Kubart vaclav.kubart at iptel.org
Mon Aug 6 11:14:59 CEST 2007


Yes, you are right.

But Maxim has introduced new module parameter by which you can say, that
NOTIFY is not target refresh request and thus NOTIFY responses won't
refresh the target.

>From my point of view is this only temporary hack (because NOTIFY was in
some discussions aggreed to be target refresh). Better solution is
probably to let the NOTIFY go through config script and process it and
its responses by nathelper.

	Vaclav

On Po, srp 06, 2007 at 10:24:17 +0200, samuel wrote:
> mmmm
> 
> coming back to the discussion....the missing OK Contact mangle happened with
> a separated prosence proxy...
> 
> I was wondering...In the case of a single SIP server
> (proxy,registrar,presence,...) when the "presence" part sends the NOTIFY to
> a natted UA and this latter one replies with the 200OK, the Contact would
> contain the internal IP and since this NOTIFY is not handled by the SER
> route config file , it can not be managed by nathelper|mediaproxy options.
> This would cause a modification in the target of the dialog to the internal
> IP (following RFC 3261) and the presence dialog would be useless because no
> notifications would work....am I right?
> 
> Thanks,
> Samuel.
> 
> 2007/8/3, samuel <samu60 at gmail.com>:
> >
> > Ok.
> >
> > I found out the "problem", there was a missing NAT handling of the
> > responses, and the 200 OK response updated the target dialog with a
> > non-routable IP. That's why further messages had the wronf Req-URI.
> >
> > Thanks for your pointers,
> > sam.
> >
> > 2007/8/2, Vaclav Kubart <vaclav.kubart at iptel.org>:
> > >
> > > Hi Samuel,
> > > Maxim Sobolev was fighting with NAT and presence some time ago.
> > >
> > > I was trying to allow calling script route block when sending NOTIFY to
> > > allow its modifications, but I had not enough time to get results.
> > >
> > > The NOTIFY should be constructed according RFC 3261; the request URI
> > > should be the value from Contact of the SUBSCRIBE request (if only loose
> > > routers in routes appear).
> > >
> > > To, From, Via and routes should follow RFC 3261 too.
> > >
> > > Contact header value is the address at which the SUBSCRIBE request
> > > arrives to the server (according examples in RFC 3856, this is
> > > controversial but possible).
> > >
> > > Modifying of async_auth_queries should have no influence on sent
> > > NOTIFYs. If does, it is probably a bug.
> > >
> > > All headers you mentioned are derived from dialog initiating SUBSCRIBE
> > > request as RFC says.
> > >
> > >         Vaclav
> > >
> > > On Čt, srp 02, 2007 at 12:05:02 +0200, samuel wrote:
> > > > Hi all!!!
> > > >
> > > > I'm experiencing quite difficulties setting up a dedicated (and
> > > separated)
> > > > presence server with NATted end-points and the dstblacklist feature.
> > > >
> > > > I'd like to get some info about the construction of the most important
> > >
> > > > headers (Req-URI,Contact,To,From,Via,Routr) for the different NOTIFY
> > > > modalities depending on the state of the subscription.
> > > >
> > > > Setting up async_auth_queries I've seen the pending and the active
> > > NOTIFY
> > > > have different Req-URI and the second one is blocked by the NAT
> > > router.
> > > > Further mid-dialog NOTIFYs providing changes in the presence status
> > > has also
> > > > different headers...
> > > > My main concern is whether the info for constructing the routing
> > > headers is
> > > > taken from location table, from watcherinfo.dialog table, or from the
> > > > incoming message...I know I could follow the code but an explanation
> > > would
> > > > provide a really helpfull overview and later checking the code will be
> > > much
> > > > simpler.
> > > >
> > > >
> > > > Thanks in advance,
> > > > Samuel.
> > >
> > > > _______________________________________________
> > > > Serusers mailing list
> > > > Serusers at lists.iptel.org
> > > > http://lists.iptel.org/mailman/listinfo/serusers
> > >
> > >
> >

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