I was doing some testing with Snom phones to try and get the phone to register to two Edge Proxies at once. With Snom you are able to configure multiple outbound proxies for a user. Snom sends a REGISTER to the first proxy without issue but the 200 response back from OpenSIPS doesn't have the following header
When I read RFC 5626 I see the following is required
The UAC examines successful registration responses for the presence
of an outbound option-tag in a Require header field value. Presence
of this option-tag indicates that the registrar is compliant with
this specification, and that any edge proxies which needed to
participate are also compliant. If the registrar did not support
Jennings, et al. Standards Track [Page 15]
RFC 5626 Client-Initiated Connections in SIP October 2009
outbound, the UA has potentially registered an un-routable contact.
It is the responsibility of the UA to remove any inappropriate
So the issue I see with the Snom phone is that it registers with the first Edge Proxy but doesn't send a REGISTER
request to the second Edge Proxy. I figure this is because it is not seeing the
Re: Does OpenSIPS support RFC 5626 (Require Outbound)
Not sure if the Route hdr is a real must - this is a preloaded Route
just in enforce the routing to EP1 (in this case). This hdr will be
consumed by the Edge Proxy - it will not be visible to the registrar.
As time as the UAC sends the REGISTER to the address of EP1, the Route
hdr is not really needed, IMHO.