A method of regulating traffic flow to customer premises devices (CPDs) reachable via outside plant units (OPUs). The method comprises receiving first packets in a first traffic category via a first interface, the first packets being destined for respective CPDs; receiving second packets in a second traffic category via a second interface, the second packets being destined for respective CPDs; determining a destination OPU for each of the first and second packets. For each particular OPU that is the destination OPU for one or more packets, the packets are buffered and transmitted via an OPU interface for the particular OPU. The destination OPU for a particular packet is determined by identifying the OPU via which the CPD for which the particular packet is destined is reachable. Packet flow via the OPU interface is regulated by prioritizing transmission of first packets over transmission of second packets.