... , DTU SERIES PHONES Nortel Networks (Northern Telecom): Meridian PBX: M3903, M3904, M3905, M2216, M2008, M2616 Meridian Norstar: M7208, M7310, M7324, T7208, T7316 ... , T7316E, M7900, M9516, M9009 Nortel 3903, 3904, 3905 Meridian Option M3110, 3310, 3820 BT Converse 220, 225, 300, 320 ...