[SR-Users] NAT problem with recvonly calls
David Cunningham
dcunningham at voisonics.com
Thu Dec 10 02:17:51 CET 2020
Thanks Alex!
On Thu, 10 Dec 2020 at 14:09, Alex Balashov <abalashov at evaristesys.com>
wrote:
> if(has_body("application/sdp") && search("a=sendonly")) [1]
>
> It's what comes to mind off the top of my head, anyway.
>
> -- Alex
>
> [1] https://www.kamailio.org/docs/modules/stable/modules/textops.html
>
> On 12/9/20 7:43 PM, David Cunningham wrote:
> > Hi Alex,
> >
> > Thank you for that. Do you offhand know of an easy way to test if the
> > sendonly attribute is set? Presumably we can use
> > sdp_remove_line_by_prefix() to remove it.,
> >
> >
> > On Wed, 9 Dec 2020 at 20:52, Alex Balashov <abalashov at evaristesys.com
> > <mailto:abalashov at evaristesys.com>> wrote:
> >
> > The salient quality of a reinvite is that has_totag() == true; it is
> > handled in the loose_route() section of your config. You want to do
> the
> > SDP manipulation in the part below that, where initial INVITEs are
> > handled.
> >
> > On 12/9/20 2:47 AM, David Cunningham wrote:
> > > Hi Daniel,
> > >
> > > Removing the sendonly from the INVITE SDP sounds like the most
> > workable
> > > solution in our case. We'd only want to do it for a new INVITE
> > though,
> > > not a re-INVITE in a situation where a call is put on hold. Would
> > you be
> > > able to give an example of such a configuration?
> > >
> > > Thanks very much for your help!
> > >
> > >
> > > On Tue, 8 Dec 2020 at 21:56, Daniel-Constantin Mierla
> > <miconda at gmail.com <mailto:miconda at gmail.com>
> > > <mailto:miconda at gmail.com <mailto:miconda at gmail.com>>> wrote:
> > >
> > > Hello,
> > >
> > > if the endpoint is not behind a port forwarding nat/firewall
> > (when
> > > one can instruct the rtp relay to use signaling address), then
> > > probably you can try to remove the sendonly from the INVITE
> SDP.
> > > That will enable rtp from endpoint to doorbell, which may rise
> > > additional concerns (e.g., privacy) if its is explicitly not
> > wanted
> > > to happen. But as Alex said in another response, the only way
> > to get
> > > it work is to make the endpoint behind nat to send a RTP
> packet.
> > > Usually the doorbells I encountered so far were accepting
> > incoming
> > > traffic as well, to discuss/interact with the person ringing
> > on it.
> > >
> > > Cheers,
> > > Daniel
> > >
> > > On 08.12.20 05:01, David Cunningham wrote:
> > >> Hello,
> > >>
> > >> We have a problem with a SIP doorbell device which sends
> > media one
> > >> way only, and NAT at the receiving device.
> > >>
> > >> When the doorbell button is pressed it makes a call to a
> > >> configured destination. Since the doorbell only sends and
> > doesn't
> > >> receive it sends the INVITE with sendonly in the SDP, and the
> > >> destination then replies with a 200 OK with recvonly in the
> SDP.
> > >> The problem is that the destination is behind NAT, and its
> reply
> > >> contains a private network IP in the SDP.
> > >>
> > >> Normally Asterisk when nat=yes works around that by
> > adjusting the
> > >> destination for RTP to be the address it actually receives
> audio
> > >> from, however because this device is recvonly Asterisk never
> > >> receives audio from it. This means Asterisk keeps trying to
> send
> > >> the doorbell's RTP to the private network IP which of course
> > >> fails, and the destination never gets the RTP from the
> doorbell.
> > >>
> > >> We haven't found a solution in Asterisk to this, so are now
> > >> looking to Kamailio which acts as a load-balancing proxy in
> > front
> > >> of Asterisk for one. For example, maybe we could use
> > >> fix_nated_sdp, but only on 200 OK's with recvonly.
> > >>
> > >> Has anyone else encountered this, and are there any
> recommended
> > >> solutions?
> > >>
> > >> Thank you in advance!
> > >>
> > >> --
> > >> David Cunningham, Voisonics Limited
> > >> http://voisonics.com/ <http://voisonics.com/>
> > <http://voisonics.com/ <http://voisonics.com/>>
> > >> USA: +1 213 221 1092
> > >> New Zealand: +64 (0)28 2558 3782
> > >>
> > >> _______________________________________________
> > >> Kamailio (SER) - Users Mailing List
> > >> sr-users at lists.kamailio.org
> > <mailto:sr-users at lists.kamailio.org>
> > <mailto:sr-users at lists.kamailio.org
> > <mailto:sr-users at lists.kamailio.org>>
> > >> https://lists.kamailio.org/cgi-bin/mailman/listinfo/sr-users
> > <https://lists.kamailio.org/cgi-bin/mailman/listinfo/sr-users>
> > <https://lists.kamailio.org/cgi-bin/mailman/listinfo/sr-users
> > <https://lists.kamailio.org/cgi-bin/mailman/listinfo/sr-users>>
> > >
> > > --
> > > Daniel-Constantin Mierla --www.asipto.com
> > <http://www.asipto.com> <http://www.asipto.com <
> http://www.asipto.com>>
> > > www.twitter.com/miconda <http://www.twitter.com/miconda>
> > <http://www.twitter.com/miconda <http://www.twitter.com/miconda>>
> > --www.linkedin.com/in/miconda <http://www.linkedin.com/in/miconda>
> > <http://www.linkedin.com/in/miconda
> > <http://www.linkedin.com/in/miconda>>
> > > Funding:https://www.paypal.me/dcmierla
> > <https://www.paypal.me/dcmierla> <https://www.paypal.me/dcmierla
> > <https://www.paypal.me/dcmierla>>
> > >
> > >
> > >
> > > --
> > > David Cunningham, Voisonics Limited
> > > http://voisonics.com/ <http://voisonics.com/>
> > <http://voisonics.com/ <http://voisonics.com/>>
> > > USA: +1 213 221 1092
> > > New Zealand: +64 (0)28 2558 3782
> > >
> > > _______________________________________________
> > > Kamailio (SER) - Users Mailing List
> > > sr-users at lists.kamailio.org <mailto:sr-users at lists.kamailio.org>
> > > https://lists.kamailio.org/cgi-bin/mailman/listinfo/sr-users
> > <https://lists.kamailio.org/cgi-bin/mailman/listinfo/sr-users>
> > >
> >
> > --
> > Alex Balashov | Principal | Evariste Systems LLC
> >
> > Tel: +1-706-510-6800 / +1-800-250-5920 (toll-free)
> > Web: http://www.evaristesys.com/ <http://www.evaristesys.com/>,
> > http://www.csrpswitch.com/ <http://www.csrpswitch.com/>
> >
> > _______________________________________________
> > Kamailio (SER) - Users Mailing List
> > sr-users at lists.kamailio.org <mailto:sr-users at lists.kamailio.org>
> > https://lists.kamailio.org/cgi-bin/mailman/listinfo/sr-users
> > <https://lists.kamailio.org/cgi-bin/mailman/listinfo/sr-users>
> >
> >
> >
> > --
> > David Cunningham, Voisonics Limited
> > http://voisonics.com/ <http://voisonics.com/>
> > USA: +1 213 221 1092
> > New Zealand: +64 (0)28 2558 3782
> >
> > _______________________________________________
> > Kamailio (SER) - Users Mailing List
> > sr-users at lists.kamailio.org
> > https://lists.kamailio.org/cgi-bin/mailman/listinfo/sr-users
> >
>
> --
> Alex Balashov | Principal | Evariste Systems LLC
>
> Tel: +1-706-510-6800 / +1-800-250-5920 (toll-free)
> Web: http://www.evaristesys.com/, http://www.csrpswitch.com/
>
> _______________________________________________
> Kamailio (SER) - Users Mailing List
> sr-users at lists.kamailio.org
> https://lists.kamailio.org/cgi-bin/mailman/listinfo/sr-users
>
--
David Cunningham, Voisonics Limited
http://voisonics.com/
USA: +1 213 221 1092
New Zealand: +64 (0)28 2558 3782
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