Extraction of Individual B Channels from a PRI Interface for the Town Council Höxter.

Task description

To install a fax server, the B-channels of four BRI-Interfaces had to be decoupled from a PRI interface of the switch. The fax server could not be installed behind the switch, as the switch supplies the old German national standard 1TR6 protocol from its’ digital ports, but the fax server requires the harmonised European protocol EDSS1.

Solution

The use of the NovaTec Network Multiplexer NNM makes uncoupling of the B-channels from the PRI Interface possible. The addressing of the required B-channels is made for the town Höxter by means of the call numbering plan and a predefined calling number index. Thus all incoming calls, which carry this index number in the calling number are not sent to the Switch, but are mediated to the fax server over one of the existing BRI-Interfaces. Then the fax server accepts the call for his part and the fax is received. All incoming calls, which do not carry this index, are sent directly to the PRI interface of the TNM and then to the switch for normal call termination by the subscriber.

Realisation

The NovaTec Network Multiplexer NNM was interconnected into the existing line of the PRI Interface between the switch and the network provider. Furthermore four BRI Interfaces from the TNM serve as a connection for the fax server.