Buffer insertion can be used very successfully for mitigation of crosstalk noise while simultaneously optimizing the effect of the insertion on the path delay. A vast majority of nets with crosstalk problems can be fixed by adding only a few buffers. This causes negligible place-and-route perturbations and allows for a convergent noise-loop closure methodology. This paper presents a novel algorithm for combining signal-integrity analysis with buffer insertion for noise and delay optimization after place-and-route.