[SR-Users] Updated NAT traversal article

Alex Balashov abalashov at evaristesys.com
Mon May 14 20:35:40 CEST 2018


Hi Sergiu,

Thanks for the suggestion! I've not encountered this on a sufficiently
widespread basis that I personally feel it merits inclusion in the
article, given its already rather broad scope. However, I will certainly
have a think on whether there it ought to be incorporated into
additional commentary of some sort on edge cases and that.

On Mon, May 14, 2018 at 01:27:23PM -0400, Sergiu Pojoga wrote:

> Hi Alex,
> 
> Glad to see the mention of SIP Outbound in your updated article. Here's
> another 5+5 cents of mine that might help others in the future.
> 
> May be you faced it, may be not, but in the multi-homed scenario that you
> describe in your article, there may be circumstances under which calls
> towards the NAT'ed phone will fail mysteriously. Reason being Firewalls of
> some ISPs or Enterprises that do packet inspection will reject such SIP
> requests due to presence of private IP addresses in the VIA and
> Record-Route headers (those of the SIP farm servers).
> 
> The solution to overcome this impediment was quite simple and unexpected
> for me - TLS encrypt your SIP traffic, which renders firewall packet
> inspection to...  a black hole :)
> 
> Same technique bypasses whatever 'smart' ALG Router there might be at
> client's premises.
> 
> Cheers,
> --Sergiu
> 
> 
> On Sat, May 12, 2018 at 2:33 AM, Alex Balashov <abalashov at evaristesys.com>
> wrote:
> 
> > Thank you, but the scope is ambitious enough that I think it would make
> > most sense to limit it to Kamailio-native approaches only.
> >
> > On May 12, 2018 8:31:58 AM GMT+02:00, Mojtaba <mespio at gmail.com> wrote:
> > >Hi,
> > >That's greats concept in this regards.
> > >I think it could be great to describe about SEMS (e.g B2BUA,
> > >NAT-Traversal) and working it with Kamailio.
> > >The SEMS has proper modules to solve NAT Traversal in Kamailio,too
> > >If you want, I could give you it's documents.
> > >Thanks With Regards.Mojtaba
> > >
> > >On Fri, May 11, 2018 at 6:43 PM, Alex Balashov
> > ><abalashov at evaristesys.com> wrote:
> > >> Hi,
> > >>
> > >> I have updated this article with some other topics:
> > >>
> > >>
> > >http://blog.csrpswitch.com/server-side-nat-traversal-
> > with-kamailio-the-definitive-guide/
> > >>
> > >> "The definitive guide" is of course an ambitious and moving target,
> > >so
> > >> there may be more evolution in the future.
> > >>
> > >> -- Alex
> > >>
> > >> --
> > >> 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
> > >
> > >
> > >
> > >--
> > >--Mojtaba Esfandiari.S
> > >
> > >_______________________________________________
> > >Kamailio (SER) - Users Mailing List
> > >sr-users at lists.kamailio.org
> > >https://lists.kamailio.org/cgi-bin/mailman/listinfo/sr-users
> >
> >
> > -- Alex
> >
> > --
> > Sent via mobile, please forgive typos and brevity.
> >
> > _______________________________________________
> > Kamailio (SER) - Users Mailing List
> > sr-users at lists.kamailio.org
> > https://lists.kamailio.org/cgi-bin/mailman/listinfo/sr-users
> >

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-- 
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/



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