Panasonic IP telephone with corded base station and 1 cordless handsetVoIP support: IETF SIP version 2(RFC3261 ands companion RFCs), BroadWorks R15 / BroadSoft, AsteriskCodec: G.711a-law / G.711m-law / G.722(wideband) / G.729a / G.726(32K)Network interface: (2) 10 / 100 base-T auto MDI / MDIX Ethernet LAN portProvisioning HTTP / HTTPS / FTP / TFTP and local / remote WEB configrationQoS support: DSCP, Static VLAN, TOSMenu driven user interfaceLine statusDirect handset call buttonsMessage waiting indicator on the base unitUS-DECT 1.92GHz 1.93GHz (for USA and Canada), EU-DECT 1.88GHz 1.90GHzExpandable up to 6 handsetsSupport for up to 8 registrationsSimultaneous voice calls2.5mm headset jackGrouping handset: handset select for receiving callHandset and number select for making callRedialDo not disturbAnonymous call (CLIR)Anonymous call rejectionBusy lamp field (BLF) for handsetsCalling party name and number presentation (CLIP, CNIP)Call rejectionDTMF dialing during call3 Party conferencingCall transferOne touch button call transferCall holdCall forward unconditional/ user busy/ no answerCall waitingDistinctive ringingRingtone selectionaccessory handset model KX-TPA50B04KXTGP550T04