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

Task description

For the installation of a fax server the task consisted of uncoupling the b-channels of four BRI-Interfaces of a PRI interface from the switch. The fax server could not be installed behind the Switch, as the switch supplies the old German national standard 1TR6 protocol from it's digital ports, but the fax server requires the harmonised European protocol EDSS1.

The Solution

The use of the TransNova^® Network Mutliplexer (TNM) 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 over one of the existing BRI-Interfaces to the fax server to be mediated, this then accepts the for his part the call and the fax is received. All in 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.

The Realisation

The TransNova^® Network Mutliplexer (TNM) 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.