A method and a communication device for processing ATM cells. The communication device includes an input interface adapted to receive an ATM cell that is associated with a PHY value and includes a pair of VCI and VPI fields. The communication device is characterized by comprising a search unit, adapted to search, within a group of memory entries that belong to a memory unit, for a pair of VCI and VPI fields that have values that match the values of the VCI and VPI fields of the received ATM cell, if the received VCI field and VPI fields belong to a first predefined group of VCI and VPI fields. The communication device further includes a processor, connected to the search unit, wherein the processor is adapted to determine a channel identifier of the received ATM cell in response to a result of the search and in response to a PHY value associated with the received ATM cell.