'IEEE P802.1Qbg/D1.5 Draft Standard for Local and Metropolitan Area Networks- Virtual Bridged Local Area Networks - Amendment XX: Edge Virtual Bridging ; 802-1qbg-d1.5', IEEE P802.1QBG/D1.5, 31 March 2011 (2011-03-31), IEEE-SA, Piscataway, NJ USA, pages 123 - 128, XP055246167