技术在快速发展进步。因此，我们建立了易于使用的术语汇编，帮助您更好地了解影响您业务的术语、技术和趋势。
A network device that receives and transmits signals to and from the wide-area-network (WAN) line. The CSU performs loopback testing of signals from the phone company and provides a barrier for electrical interference from either side of the unit (customer premises or phone company).
