The "Interworking Element for 8 E1/T1 lines" (IWE8), PXB 4220 and PXB 4221 are members of Infineon" ATM Chipset. Together with framing and line interface components (e.g. Infineon's QuadFALC PEB 22554) the IWE8 serves as gateway between Asynchronous Transfer Mode (ATM) networks and timeslot based PDH networks. The IWE8 is a single chip multiservice device that integrates ATM cell handling and TDM circuit to ATM cell interworking in E1/T1 applications. Each of the 8 E1 or T1 input and output ports can be configured independently to operate in ATM Mode or AAL Mode. It is a very flexible solution supporting multiple services with a minimum of devices.