EWSD

EWSD (Elektronisches Wählsystem Digital in German, Electronic Digital Switching System/Electronic World Switch Digital in English) is one of the most widely installed telephone exchange systems in the world. EWSD can work as a local or tandem switch or combined local/tandem, and for landline or mobile phones. It is manufactured by Siemens AG, who claims that EWSD switches perform switching for over 160 million subscriber lines in more than 100 countries.