A packet, cell or other data segment received in a physical layer device from a link layer device via an interface bus is processed to determine a port address for the data segment in the physical layer device. The port address, which may be an MPHY address, is determined using a combination of a first address value obtained from a link layer address portion of the data segment and a second address value obtained from a payload portion of the data segment. The data segment is stored in a memory location identified by the port address. The memory location may comprise a particular queue of the physical layer device.