Performance impacts due to number portability under various routing schemes

Number portability provides users the capability to keep their telephone numbers as they moves to another provider. Number portability technology involves complicated architecture between different providers. From a routing perspective, and in order to simplify the model, we consider that the traversal of a call to a ported number may involve three different networks: the Originating Network, the Donor Network, and the Recipient Network. In this work, we consider four routing schemes, Onward Routing (OR), Query on Release (QoR), Call Dropback/Return to Pivot (CD/RtP), and All Call Query (ACQ) for number portability. We present preliminary results on their performances under various scenarios from a connection setup delay point of view when the rate of portability changes.