The configuration of the SIP client or connection to the SIP PBX as a SIP PBX line named 'HQ' has already been described in other example applications and, here, is assumed to be familiar to you. The SIP PBX at headquarters uses the SIP domain 'mycompany.HQ' and the branch office has the internal domain 'mycompany.BRANCH01'.
This is how the LANCOM is configured for operation at a point-to-point line:
- The ISDN mapping table translates the DDI (extension numbers) to the internal numbers for processing as SIP calls.
| MSN/DDI | ISDN/S0 Bus | Internal number | Comment |
|---|---|---|---|
| 0 | ISDN1, ISDN2 | 300 | Maps DDI '0' to internal number '300' |
| # | ISDN1, ISDN2 | 3# | Adds the prefix '3' to all other DDI '0' for the internal numbers |
- Both entries in this example apply to the ISDN interfaces 1 and 2, which are connected to the ISDN line. The activation of two ISDN interfaces makes four B channels available for use. If both B channels of an ISDN interface are engaged, there is an automatic attempt to redirect calls to another ISDN interface with free B channels.
- Based on the ISDN user entries, the internal numbers are translated back to the DDI numbers.
| Internal number | MSN/DDI | ISDN/S0 Bus | Comment |
|---|---|---|---|
| 300 | 0 | ISDN3, ISDN4 | Maps internal number '300' to DDI '0'. Useful if the exchange is on the ISDN PBX. |
| 31# | 1# | ISDN3, ISDN4 | Removes the leading '3' from all internal numbers beginning with '3'. |
- With the second entry, all ISDN terminal devices with the ISDN extension
numbers '10' to '19' are made known to be ISDN users in the VoIP system.
A single entry here suffices for all subscribers. All ISDN users then
use the same data to register at the SIP PBX.
Note: ISDN users entered with the # symbol can only be reached from the SIP PBX if this does not require users to register. For ISDN users to register, separate entries in the ISDN user list are required.Both entries in this example apply to the ISDN interfaces 3 and 4, which are connected to the ISDN PBX. Here, too, the four B channels of the two interfaces can be used "dynamically" for the connection between the ISDN PBX and the LANCOM VoIP Router.
- Routing of calls is governed by the call routing table. If you use the LANconfig Wizard, the call-routing table is preset so that all outgoing calls from ISDN and SIP devices are conducted via the SIP PBX with the exception of local calls and calls to service numbers, such as 0800 numbers.