[SR-Users] sip invite proxy-authorization

[Alex Balashov]

Hi,

On Fri, Jan 19, 2018 at 03:38:24PM -0000, Dave & Hazel wrote:

> preforming a SIP INVITE without first registering with the Kamailio
> service (SJ-Phone speak). I am dialling in remotely via NAT and my
> call is being relayed successfully.

Although many people are led to believe that there is some intrinsic
connection between registration and outbound calling by the way phone
UIs present these concepts, there is in fact no such connection
whatsoever. 

Registration is an inbound concept, not an outbound concept. You can
make calls without being registered. You can make outbound calls using
different AAA mechanisms. Being registered in no way implies being able
to make outbound calls. They're just completely unrelated.

There is a common authentication mechanism used in both scenarios:
digest challenge authentication. As a practical matter, Kamailio sends a
407 proxy challenge for requests it is meant to relay (e.g. INVITEs) and
a 401 Unauthorized challenge for requests of which it is the logical
destination (e.g. REGISTER), and both draw on the same set of
authentication credentials and otherwise work the same way. The AUTH
route covers both of these cases.

-- 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/