By default, the load-balancer listens on the UDP and TCP ports 5060 (kamailio→lb→port) and TLS port 5061 (kamailio→lb→tls→port). If you need to setup one or more extra non-standard SIP listening ports in addition to those standard ports, please edit the kamailio→lb→extra_sockets option in your /etc/ngcp-config/config.yml file.

The correct format consists of a label and value like this:

    extra_sockets:
      port_5064: udp:10.15.20.108:5064
      test: udp:10.15.20.108:6060

The label is shown in outbound_socket peer preference (if you want to route calls to specific peer out via specific socket); the value must contain a transport specification as in example above (udp, tcp or tls).

	in this case you have just added an extra SIP listening port. RTP traffic will still use your default IP address.

If you want to use one more interface (with a different IP address) for SIP signalling and also RTP traffic (for example you need that connect to a spefici peering server), what you need to do is to add your new interface in the /etc/network/interface file. After that the new interface should be declared in /etc/ngcp-config/network.yml . Let’s supposed to add a new SIP socket and a new RTP socket on VLAN 100:

..
..
    eth0.100:
      hwaddr: ff:ff:ff:ff:ff:ff
      ip: 192.168.1.3
      netmask: 255.255.255.0
      type:
        - sip_ext
        - rtp_int_100
..
..
    interfaces:
      - lo
      - eth0
      - eth0.100
      - eth1
..
..

Then, in order to use the new vlan100 IP as SIP signalling socket towards your peering a label (int_100 for example) must be added in /etc/ngcp-config/config.yml :

    extra_sockets:
      port_5064: udp:10.15.20.108:5064
      test: udp:10.15.20.108:6060
      int_100: udp:192.168.1.3:5060

Finally changes have to be applied:

ngcpcfg apply 'added extra SIP and RTP socket'

After have applied the changes, a new SIP socket will listen on IP 192.168.1.3 and this socket can now be used as source socket to send SIP messages to your peer for example. The new label "int_100" is now shown in outbound_socket peer preference. Also, RTP socket is now listening on 192.168.1.3 and you can choose the new RTP socket to use by setting parameter rtp_interface to the Label "int_100" in your Domain/Subscriber/Peer preferences.