Trunk Planning

When performing trunk planning for PSTN or other public TDM-based network, two types of traffic needs to be considered:

Traditional links that connect the PBX to the public network, and the capacity needed for this type of traffic.
The amount of trunks needed for extension services like mobile extension and remote extension.

Note:

Some countries or operators might require an inter-working unit, like for example, a Channel Service Unit (CSU) in the USA, to connect the system to the public network.

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