AT-IP622 Standard Business Voip Phone Applications:MAC address cloningSIP proxy redundancy :dynamic via DNS SRV,A recordsDirect IP to IP callingNAT Traversal:Traversal by STUNBuilt-in NAT routerQOS with Layer 2 and layer 3DHCP Server and ClientIP confilict detectionSupport POE comply with IEEE802.3af(optional) Call Features:4 linescall waitingAuto AnswerMusic on holdCaller ID and call waiting ID3-way conferencecall holdcall forwardingcall mutecall transfer:blind transfer and attended transferdelayed hotlineSMS FunctionsRedialSpeed DialBLFPick upcall parkDial planphonebookblack listMWIcall log:redial list,answerd calls and missed callsDNDFull-duplex speakerphoneVolume adjustment:handset,speaker and ringerDTMF Relay:in-band,out-band(RFC2833)and SIP INFOCustomized ring toneSMS(100 records)call history(100 records)-most recently missed calls/received calls/dialed numbersphone book(100 records)speed dial (10 records) Dimension: 191*205*75(mm) L*W*H Weight: 720g(without package)