Trunks

For existing and new systems, own extension number range must be added in PNR to achieve routing of calls that are addressing the now vacant extensions. Existing tie-lines interconnecting the affected systems are left untouched assuming that PNR has been used for routing in the private network.

External/public trunks, e.g. PSTN/ISDN are moved as appropriate for the assumed traffic load in order to minimize tie-line utilization for incoming and outgoing trunks. Trunks that only support outgoing traffic, can be active in both systems in order to mini­mize this traffic, as MX-ONE will use own outgoing trunks. In this case, alternative routing over the tie-line is recommended for the public destination.

Traffic distribution for incoming trunks is outside MX-ONE’s control. If all users in a full DID range have moved, the PSTN/ISDN should be capable of routing calls to the correct system, so coordination with the network operator is needed for the timing and execution of this change.

The temporary tie-line routes between the old and the new system must be dimen­sioned in relation to the number of moved extensions, so the expected traffic capacity can be handled by the tie-lines.