Interconnect two Wazo directly

Interconnecting two Wazo will allow you to send and receive calls between the users configured on both sides.

The steps to configure the interconnections are:

  • Establish the trunk between the two Wazo, that is the SIP connection between the two servers
  • Configure outgoing calls on the server(s) used to emit calls
  • Configure incoming calls on the server(s) used to receive calls

For now, only SIP interconnections have been tested.

Establish the trunk

The settings below allow a trunk to be used in both directions, so it doesn’t matter which server is A and which is B.

Consider Wazo A wants to establish a trunk with Wazo B.

  • POST /trunks {"context": <see below>}
  • POST /endpoints/sip {"username": "wazo-trunk", "secret": "pass", "type": "friend", "host": "dynamic"}
  • PUT /trunks/{trunk_id}/endpoints/sip/{sip_id}

The context field will determine which extensions will be reachable by the other side of the trunk:

  • If context is set to default, then every user, group, conf room, queue, etc. that have an extension if the default context will be reachable directly by the other end of the trunk. This setting can ease configuration if you manage both ends of the trunk.
  • If you are establishing a trunk with a provider, you probably don’t want everything to be available to everyone else, so you can set the context field to from-extern. By default, there is no extension available in this context, so we will be able to configure which extension are reachable by the other end. This is the role of the incoming calls: making bridges from the from-extern context to other contexts.

On Wazo A, create the other end of the SIP trunk:

  • POST /trunks {"context": "from-extern"}
  • POST /endpoints/sip {"username": "wazo-trunk", "secret": "pass", "type": "friend", "host": <Wazo B IP address or hostname>}
  • PUT /trunks/{trunk_id}/endpoints/sip/{sip_id}
  • POST /registers/sip {"auth_username": "wazo-trunk", "auth_password": "pass", "transport": "udp", "remote_host": <Wazo B IP address or hostname>}
  • PUT /trunks/{trunk_id}/registers/sip/{sip_id}

On both Wazo, activate some codecs:

  • PUT /asterisk/sip/general {..., "allow": "gsm", ...}

At that point, the Asterisk command sip show registry on Wazo B should print a line showing that Wazo A is registered, meaning your trunk is established.

Set the outgoing calls

The outgoing calls configuration will allow Wazo to know which extensions will be called through the trunk.

On the call emitting server(s), add outgoing call.

  • POST /outcalls
  • PUT /outcalls/{outcall_id}/trunks
  • POST /extensions {"exten": "_**99.", "context": "to-extern"}
  • PUT /outcalls/{outcall_id}/extensions/{extension_id} {"strip_digits": 4}

This will tell Wazo: if any extension begins with **99, then try to dial it on the trunk wazo-trunk, after removing the 4 first characters (the **99 prefix).

The most useful special characters to match extensions are:

_ (underscore): tells Asterisk that this is a pattern
. (period): will match one or more characters
X: will match only one character

You can find more details about pattern matching in Asterisk (hence in Wazo) on the Asterisk wiki.

Set the incoming calls

Now that we have calls going out from a Wazo, we need to route incoming calls on the Wazo destination.

Note

This step is only necessary if the trunk is linked to an Incoming calls context.

To route an incoming call to the right destination in the right context, we will create an incoming call

  • POST /extensions {"exten": "101", "context": "from-extern"}
  • POST /incalls {"destination": {"type": "user", "user_id": <someone_id>}}
  • PUT /incalls/{incall_id}/extensions/{extension_id}

This will tell Wazo: if you receive an incoming call to the extension 101 in the context from-extern, then route it to the user someone_id. The destination context will be found automatically, depending on the context of the line of the given user.

So, with the outgoing call set earlier on Wazo A, and with the incoming call above set on Wazo B, a user on Wazo A will dial **99101, and the user someone_id will ring on Wazo B.