11. Network Configuration

Starting with version 2.7, the sip:provider CE uses a dedicated network.yml file to configure the IP addresses of the system. The reason for this is to be able to access all IPs of all nodes for all services from any particular node in case of a distributed system on one hand, and in order to be able the generate /etc/network/interfaces automatically for all nodes based on this central configuration file.

11.1. General Structure

The basic structure of the file looks like this:

hosts:
  self:
    role:
      - proxy
      - lb
      - mgmt
    interfaces:
      - eth0
      - lo
    eth0:
      ip: 192.168.51.213
      netmask: 255.255.255.0
      type:
        - sip_ext
        - rtp_ext
        - web_ext
        - web_int
    lo:
      ip: 127.0.0.1
      netmask: 255.255.255.0
      type:
        - sip_int
        - ha_int

Some more complete, sample configuration is shown in network.yml Overview Section B.3, “network.yml Overview” section of the handbook.

The file contains all configuration parameters under the main key: hosts

In sip:provider CE systems there is only one host entry in the file, and it’s always named self.

11.1.1. Available Host Options

There are three different main sections for a host in the config file, which are role, interfaces and the actual interface definitions.

role: The role setting is an array defining which logical roles a node will act as. Possible entries for this setting are:
- mgmt: This entry means the host is acting as management node for the platform. In a sip:provider CE system this option must always be set. The management node exposes the admin and CSC panels to the users and the APIs to external applications and is used to export CDRs.
- lb: This entry means the host is acting as SIP load-balancer for the platform. In a sip:provider CE system this option must always be set. The SIP load-balancer acts as an ingress and egress point for all SIP traffic to and from the platform.
- proxy: This entry means the host is acting as SIP proxy for the platform. In a sip:provider CE system this option must always be set. The SIP proxy acts as registrar, proxy and application server and media relay, and is responsible for providing the features for all subscribers provisioned on it.
- db: This entry means the host is acting as the database node for the platform. In a sip:provider CE system this option must always be set. The database node exposes the MySQL and Redis databases.
- rtp: This entry means the host is acting as the RTP relay node for the platform. In a sip:provider CE system this option must always be set. The RTP relay node runs the rtpengine NGCP component.
interfaces: The interfaces setting is an array defining all interface names in the system. The actual interface details are set in the actual interface settings below. It typically includes lo, eth0, eth1 physical and a number of virtual interfaces, like: bond0, vlanXXX
<interface name>: After the interfaces are defined in the interfaces setting, each of those interfaces needs to be specified as a separate set of parameters.

Addtional main parameters of a node:

dbnode: the sequence number (unique ID) of the node in the database cluster; not used in sip:provider CE system

11.1.2. Interface Parameters

hwaddr: MAC address of the interface
ip: IPv4 address of the node
v6ip: IPv6 address of the node; optional
netmask: IPv4 netmask
advertised_ip: the IP address that is used in SIP messages when the NGCP system is behind NAT/SBC. An example of such a deployment is Amazon AMI, where the server doesn’t have a public IP, so load-balancer component of NGCP needs to know what his public domain is (→ advertised_ip).
type: type of services that the node provides; these are usually the VLANs defined for a particular NGCP system.
You can assign a type only once per node.
Available types are:
- api_int: internal, API-based communication interface. It is used for the internal communication of such services as faxserver, fraud detection and others.
- aux_ext: interface for potentially insecure external components like remote system log collection service.
- mon_ext: remote monitoring interface (e.g. SNMP)
- rtp_ext: main (external) interface for media traffic
- sip_ext: main (external) interface for SIP signalling traffic between NGCP and other SIP endpoints
- sip_ext_incoming: additional, optional interface for incoming SIP signalling traffic
- sip_int: internal SIP interface used by NGCP components (lb, proxy, etc.)
- ssh_ext: command line (SSH) remote access interface
- web_ext: interface for web-based or API-based provisioning and administration
- web_int: interface for the administrator’s web panel, his API and generic internal API communication


	Please note that, apart from the standard ones described so far, there might be other types defined for a particular NGCP system.

vlan_raw_device: tells which physical interface is used by the particular VLAN
post_up: routes can be defined here (interface-based routing)
bond_XY: specific to "bond0" interface only; these contain Ethernet bonding properties

11.2. Advanced Network Configuration

You have a typical deployment now and you are good to go, however you may need to do extra configuration depending on the devices you are using and functionality you want to achieve.

11.2.1. Extra SIP Sockets

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 SIP listening ports or IP addresses 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 the outbound_socket peer preference (if you want to route calls to the specific peer out via specific socket); the value must contain a transport specification as in example above (udp, tcp or tls). After adding execute ngcpcfg apply:

ngcpcfg apply 'added extra socket'

The direction of communication through this SIP extra socket is incoming+outgoing. The sip:provider CE will answer the incoming client registrations and other methods sent to the extra socket. For such incoming communication no configuration is needed. For the outgoing communication the new socket must be selected in the outbound_socket peer preference. For more details read the next section Section 11.2.2, “Extra SIP and RTP Sockets” that covers peer configuration for SIP and RTP in greater detail.


	In this section you have just added an extra SIP socket. RTP traffic will still use your rtp_ext IP address.

11.2.2. Extra SIP and RTP Sockets

If you want to use an additional interface (with a different IP address) for SIP signalling and RTP traffic you need to add your new interface in the /etc/network/interfaces file. Also the interface must be declared in /etc/ngcp-config/network.yml.

Suppose we need to add a new SIP socket and a new RTP socket on VLAN 100. You can use the ngcp-network tool for adding interfaces without having to manually edit this file:

ngcp-network --set-interface=eth0.100 --ip=auto --netmask=auto --type=sip_ext_incoming --type=rtp_int_100

The generated file should look like the following:

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

As you can see from the above example, extra SIP interfaces must have type sip_ext_incoming. While sip_ext should be listed only once per host, there can be multiple sip_ext_incoming interfaces. The direction of communication through this SIP interface is incoming only. The sip:provider CE will answer the incoming client registrations and other methods sent to this address and remember the interfaces used for clients' registrations to be able to send incoming calls to him from the same interface.

In order to use the interface for the outbound SIP communication it is necessary to add it to extra_sockets section in /etc/ngcp-config/config.yml and select in the outbound_socket peer preference. So if using the above example we want to use the vlan100 IP as source interface towards a peer, the corresponding section may look like the following:

    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

The changes have to be applied:

ngcpcfg apply 'added extra SIP and RTP socket'

After applying 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. In above example we used label int_100. So the new label "int_100" is now shown in the 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.