Ring-based WDM-PONs can employ a single dedicated wavelength channel to interconnect the Optical Network Units (ONUs) thus providing a means for inter-ONU communication and downstream wavelength sharing. In this paper, a new TDM dynamic bandwidth allocation (DBA) algorithm for inter-ONU communication is proposed, which takes into account the destination of the ONUs on the ring. The main purpose of this `Destination-Aware' (DestAware) algorithm is to improve the network inter-ONU communication performance without any additional cost. Performance results show that by considering the destination of the ONUs during the bandwidth allocation process both line utilization and experienced delay are improved.