The third and last way is to add an external extension over the given user. In the Users – Users & Groups menu select the user, display the context menu and click Add extension. Complete the extension name and number and enable the Resend SMS option if necessary. See Figure 2 above again.
Having added an external extension and saving the configuration, check the external extension for a valid licence on the Basic tab in the Required licences section on the extension level. Refer to the Global data – Licences menu for the total count of the Mobility Extension user licences.
Figure 2: View of External Extension Routing Tab
As shown in Fig. 3, incoming calls from an external extension are routed to the DISA dial-in. See Figure 3 for specific DISA settings. With this configuration, the incoming call is routed to the Default router. Then a 10-second dialling timeout follows, which is detected by the DTMF detector (to include it, check the DTMF option in the lower part). If the 10-second timeout expires without dialling detection, the call is routed to the Operator extension.
Figure 3: View of DISA Configuration for Mobility Extension
The Default router usually gives the user a much broader scope of operation than the above-mentioned Internal router because it is one level higher in the hierarchical structure. It allows the user to call internal extensions, use the services and also call public networks. Restriction of calling international numbers can be achieved, for example, by including an authorisation router.
To distinguish the rights of different external extensions, just create multiple DISA dial-ins and routers and assign different routers to groups with identical rights in the DISA to specify the calling user rights.
Figure 5: Part of Configuration of External Extension with Number Used for Routing
The port via which the call is to be made determines the setup of the Without port routing on the Routing tab in the extension properties (or, as the case may be, the type of the extension when using mass configuration by the fall-down structure). Figure 2 shows a suitable routing solution for an outgoing call of an external extension. The inclusion of a bundle of GSM ports in the Without port routing reduces the probability of call rejection at the respective external extension when one GSM port is busy at the moment.
One of the possible settings of the bundle is shown in Figure 6. The selected cyclic allocation strategy means that at the first attempt to call one of the external extensions with this bundle set in the Without port routing, the call is routed to the first row of the bundle, i.e. to port GSM 1. At the second call attempt it is routed to port GSM 2, subsequently to port GSM 3, and then to port GSM 1 again. In case the specific port is busy at the moment of routing, the next row is automatically used. To ensure this, check the Next row if caller busy option. In case all the ports are busy, the call can be routed to the Default destination, which is a back-up solution.
Figure 6: Typical Configuration of GSM Port Bundle for Outgoing Routing to External Extension
*** Verify also with a provider that allows to send outgoing CLIP in a certain format, it might be useful to set based on the providers request in the section Users - Properties - Customer - Facility to yes (enable/disable sending of the Facility or Redirecting number in signalling for the given level).
What Is necessary for SMS at No Answer
Figure 7: Typical Settings for Sending SMS at No Answer
What Is Necessary for Routing Outgoing SMS to External Extension
Figure 8: View of Typical Settings for Message Routing to External Extension
To make SMS sending to an external extension work properly, check the Resend SMS option in the configuration. The flow chart for SMS sending to an external extension is included in Annex 3. The procedure of forwarding of SMS received by the external extension user is shown in Annex 4.
Annex 1: Flow Chart Showing Processes for Incoming Call from External Extension