Here are the results of your search through the public section of the IEEE Standards OUI database report for 00-20-8F:
00-20-8F (hex) ECI TELECOM LTD. 00208F (base 16) ECI TELECOM LTD. HASIVIM ST. 30, PETACH-TIKVA 49133 ISRAEL
Your attention is called to the fact that the firms and numbers listed may not always be obvious in product implementation. Some manufacturers subcontract component manufacture and others include registered firms' OUIs in their products.