This paper considers a problem of configuring logical networks by employing a self-planning facility in a telecommunication network carrying voice-grade calls to make the least-cost configuration where the involved system cost includes hop cost and lost-call traffic cost. The hop cost depends on the number of self-planning facilities included on routing path connecting the associated node pairs, while the lost-call traffic cost is incurred due to link capacities. The configuration problem is analyzed through dimensioning and routing on a reconfigurable network in a mixed 0/1 nonlinear programming approach for which lower bounds are found by Lagrangian relaxation embedded in a hybrid search procedure for the associated dual problem. Heuristic solution procedures are exploited and their efficiencies are tested with various numerical examples.