Trunks.md - edlentz/Nimbus GitHub Wiki

Trunks are usually SIP or IAX (IAX trunks are special trunks to connect two Asterisk systems together so they can intercom between themselves and also share resources). These trunks are in addition to trunks from the DAHDI cards.

The trunk name and the Outbound CallereID are important. There ia also a Disable trunk. This is handy when you want to force the trunk to reconnect to the provider.

The trunk setting for outgoing and incoming are similar in some instances. These peer details are extremely important without even one of these entries the trunk will fail. Each provider requires different settings. So if you need to setup a trunk you are unfamiliar with, seek out the trunk provider tech supprt for an example setup for Freepbx.

There are two different connections for SIP trunks as far as security is concerned. The first is Registration based. For the peer details a username and password are used to authenticate to the provider. This method allows the WAN address of the local network to change and the trunks will connect. The second is called Ip Authentication. The WAn of the system is a static IP address. The provider is given this IP and will only allow a conection from that address. This is the type of connection the example is using above.