LCD 2-Line, 16-Character Protocol SIP (RFC3261) Support Codecs G.711 a-law/?-law, G.729A Call Log (Incoming/Missed) 50 Redial Last 10 numbers Ringer Pattern 3 Ringer Volume Control 4-Step + OFF PBX Compatibility KX-NCP500/1000: PBMPR Software File Version 1.0 or later KX-TDE100-200: PMMPR Software File Version V2.01 or later KX-TDE600: PGMPR Software File Version 2.0 or later