To resolve the performance decrease of FIRM under non-uniform traffic, a pointer strategy optimized algorithm named low-FIRM is proposed. This scheduling algorithm modifies round-robin pointers of each input queue according to the weight of the length and waited time of each virtual output queue, which makes the queue with largest weight tend to be served first. Low-FIRM is described and its performance is compared with those of iSLIP and FIRM. Simulation results show that low-FIRM achieves high performance under both of the uniform and non-uniform traffic.