Hi,
On Dec 23, 2022, at 2:15 AM, Benoît Panizzon benoit.panizzon@imp.ch wrote:
So towards some 'endpoints' I would need an IP in the Via and towards others I would need a hostname.
Could this dimension of the problem, at least, perhaps be solved with two listeners, albeit on different ports, which have different 'advertised' addresses?
listen=udp:1.1.1.1:5060 advertised 2.2.2.2:5060 listen=udp:1.1.1.1:5070 advertised dns.fqdn.host:5060
But I realised, we most probably have to re-consider our idea to run all our kamailio instances in a load-balanced DMQ master-master set-up.
A CPE, even when the NAPTR entry or DNS Hostname it registers to points to multiple registrar instances, in the end registers to ONE ip address. In a NAT scenario, this is the IP which the SIP ALG on the customer firewall handles.
In a Master-Master registrar scenario, the INVITE towards a CPE might originate from the IP of the registrar that CPE did not register to and therefore the SIP ALG not knowing about and never make it through NAT.
I do agree that this approach is a bit idealistic, mostly because of NAT.
This is the problem SIP Outbound (RFC 5626) was created to solve, but it requires rather explicit support on the CPE, which, at the last time I last looked into it, did not seem to be widespread.
-- Alex